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S T U D E N T'S 



PRACTICAL CHEMISTRY. 

EXGKAtCE ' 

CHEMICAL PHYSICS AND INORGANIC AND 
ORGANIC CHEMISTRY. 




BY 



HENRY MORTON, Ph.D., AND ALBERT R. LEEDS, A.M., 

EMeViTCS PROFESSOE of chemistry in the professor of chemistry and METALLUROl 

PHILADELPHIA DENTAL COLLEGE; ALSO IN THE PHILAOELpklA DENTAL COLLEGE, 

PROFESSOR OF MECHANICS AND AND LECTURER ON CHEMISTRY IN 

RESIDENT SECRETARY OF THE THE FRANKLIN INSTITUTE 

FRANKLIN INSTITUTE. OF PENNSYLVANIA. 



PHILADELPHIA 

J. B. LIPPINCOTT & CO. 

1874. 



Entered according to Act of Congress, in the year 1865, hj 

J. B. LIPPINCOTT & CO. 

In tile Clerk's Office of the District Court of the United States for the ISutera 
District of Pennsylvania. 



:Ii':b.fieol.^^vW 



PREFACE 



The authors of the following pages have made 
it their object to produce a book of practical use to 
the student, by furnishing him with clear and simple 
explanations of the subject ; and to those more pro- 
ficient in scientific learning, by giving them in small 
compass, convenient memoranda of important facts, 
numbers, references, etc. The effort has also been 
made to embody all the valuable novelties in the 
branches discussed (many of which have not yet been 
introduced in any text book), and thus to bring this 
work down to the present time. 

In the explanation of laws and theories, mathemat- 
ical precision of statement has been less studied than 
the expression of a clear idea, in such form as would 
be readily apprehended by one not previously con- 
versant with the subject. Thus, such explanations 
as those on pages 80 and 62 may be well passed over 

(iii) 



iv PREFACE. 

by tlie well-read man of science; as partaking more 
of the nature of similes than precise statements; but 
they will have done the work intended for them, if 
they famish the beginner with such a general view 
of the subject concerned, as will aid him in recollect- 
ing its facts, and pave the way for a more precise 
and abstract idea, in the future. 



CONTENTS 



Part I, 



CHEMICAL PHYSICS. 



PAOE. 

General Properties of Matter .... 9-10 

Mechanical Forces ..... 10 

Gravitation — Specific Gravity .... J 0-1 2 

Cohesion — Adhesion — Capillary Attraction — Diffusion 12-15 

Repulsion ...... 15 

Polarity ...... 16 

Heat . . . . . . . . 16-37 

Sources . . . . . . 17-18 

Measurement ...... 18-19 

Specific Heat . "* . . . . 20-21 

Effects of Heat . . . . . .21-33 

Expansion ..... 21-23 

Fusion — Latent Heat — Freezing Mixtures . . 23-26 
Vaporization — Latent Heat — Freezing by Evapo- 
ration—Distillation .... 26-33 

Transfer of Heat . . . . . 33-37 

Conduction — Spheroidal State . .. . 33-35 

Convection ...... 35-36 

Radiation ...... 36-37 

Light ....... 88-71 

Sources ...... 38 

Interference — Diffraction .... 39-40 

Reflection ...... 41-45 

Refraction — Lenses — Double Refraction . . 45-51 

Composition — Prisms .... 61-58 

Spectrum Analysis ..... 55-56 

Absorption Bands .... 56-58 

Fluorescence and Phosphorescence . . . 58-59 

Dispersion ...... 60-62 

Polarized Light ...... 62-71 

1* (y) 



vi CONTENTS. 






Electricity, Thkokt of 


. 


71-89 


Statical Electricity — Positive and 


Negative — Con- 


ductors 


, , 


. 72-75 


Electrical Machines 


, 


75-76 


Attraction and Repulsion 


, 


. 76-81 


Induction — Electrophorus — Leyden Jars 


81-83 


Transfer of Electricity — Geissler Tubes 


. 83-89 


Magnetism .... 




89-94 


Permanent Magnets . 




. 90-92 


Electro-Magnets . 




92-94 


Galvanism 




. 94-122 


Galvanic Batteries 




96-104 


Effect of the Galvanic Current 




. 105-122 


Heating and Luminous 




105-107 


Chemical . . . 




. 107-110 


Mechanical . . . 




110-114 


Galvanic Induction 




. 114-120 


The Ruhmkorff Coil 




117-119 


Thermo-Electricity . 




. 120-121 


Animal Electricity 




121-122 



I>art II. 

CHEMISTRY— GENERAL DEFINITIONS. 

Thbes Chabactebistics of Chemical Affinity . . 123-125 

INORGANIC CHEMISTRY. 



Elements 


. 


. 


. 125-126 


Nomenclature — Symbols — Atomic 


Weights 


126-127 


Binaries 


, 


. , 


. 127-128 


Acids — Bases — Neutrals 




, , 


128-130 


Tebnabies 


. 


, 


130 


Nomenclature of Oxygen and 


Sulphur Salts 


130 


Metalloids . 


. 




. 131-177 


Oxygen — Ozone and Antozone . 






131-138 


Hydrogen and its Compounds 


, 




. 138-143 


Nitrogen 






143-144 


Air — Hygrometers 


, 




. 144-146 


Compounds of Nitrogen 






146-151 


Chlorine and its Compounds 


, 




. 151-155 


Bromine .... 






155 


Iodine 


, 




156 


Fluorine 






156-157 


Carbon — Its Three Modifications 


, 




. 158-159 


Compounds of Carbon 






160-165 


Boron 






. 165-166 


Silicon— Silica . 






166-168 



CONTENTS. 



VU 



Sulphur ....•• 


. 168-169 


Sulphurous, Sulphuric and Hydrosulphuric Acid . 


169-173 


Selenium . . 


174 


Phosphorus . . . 


174-177 


METALS. 




Physical and Chemical Propertibs of Metals . 


. 177-179 


Salts ....... 


179-180 


GROUP I. 




Potassium ...... 


. 181-185 


Sodium ...... 


186-189 


Lithium . . . . . 


189 


Ammonium ...... 


190-191 


GROUP II. 




Barium ..... 


192-193 


Strontium ..... 


193 


Calcium ...... 


193-196 


Magnesium ..... 


. 196-198 


GROUP IIL 




Aluminum, etc. . . . 


198-201 


Metals lately Discovered by Spectral Analysis 


202 


GROUP IV. 




Manganese ..... 


202-204 


Iron . . . . . 


. 205-209 


Cobalt ...... 


209 


Nickel ...... 


210 


Chromium ..... 


211-212 


Zinc ...... 


. 212-213 


Cadmium— Copper .... 


214 


Lead . ..... 


. 215-217 


Bismuth . 


217-218 


Uranium ...... 


218 


GROUP V. 




Tungsten— Vanadium— Molybdenum 


219 


Tellurium— Arsenic .... 


220-222 


Titanium— Tin ..... 


222 


Antimony ..... 


223-224 


Tantalum— Columbium .... 


224 


GROUP VL 




Mkrcury . . . 


224-225 


Silver ...... 


225 


Gold — Platinum .... 


226-227 


Palladium ..... 


227 


Iridium— Osmium— Ruthenium— Rhodium . 


228 


ORGANIC CHEMISTRY. 




Classification of Organic Bodies . 


. 228-230 


I. Saccharine and Amylacbous Bodies 


230 


\. Starch ..... 


. 280-231 



vm 



CONTENTS. 



Saccharine and Amylaceous Bodies continued. 

2. Gum ..... 

3. Lignine . . " . 

Creosote — Paraffine — Coal-Tar — Naphthalin 

4. Sugar ..... 

Fermentation .... 
Alcohols ..... 
Ether ..... 
Products of Oxidation of Alcohol 
Action of Chlorine and Sulphur on Alcohol 
Formic Acid .... 
n. Ethtl — Methyl, Etc. 
Kakodyl 

Propyl — Butyl — Amyl 
Benzoyl — Cinnamyl — Salacyl 
Vegetable Acids . . 

Oxalic — Tartaric 
Citric 

Malic — Tannic — Gallic . 
Obganic Basks . 

I. Organic Alkalies, oe Alkaloids 

II. Artificial Alkaloids 

III. Artificial Alkaloids 

IV. Artificial Alkaloids 

POUND Radicals 

V. Oils 
(«) 



Homologous with Aniline 
Containing several Com- 



Fixed Oils, or Fats .... 
Saponification .... 

Soap-Making — Candle-Making . 
(6) Essential or Volatile Oils 

(a) Hydrocarbon Essential Oils . 

(b) Oxyhydrocarbon Essential Oils 

Camphors — Resins and Balsams 
(c) Essential Oils Containing Sulphur 

VI. Cyanogen and its Compounds 

VII. Organic Coloring Principles . . « . 

Litmus — Madder — Safflower — Brazil-wood — Log' 
wood — Quercitron — Fustic-wood — Saffron- 
Turmeric — Cochineal — Chloropbyle 

VIII. Albuminous Bodies .... 

Protein — Albumen — Casein — Gelatin — Kreatin — 
Blood, Etc. .... 

Appendix ...... 

Index ...... 



NOTES ON CHEMISTRY, 

PART I. 



CHEMICAL PHYSICS. 

In consequence of the close relation existing between 
various physical forces, and the sciences which discuss 
them, it is necessary in treating one subject, to use some 
terms belonging strictly to other affiliated departments. 
Thus in our present abstract of Chemistry, many terms 
of Mechanics, Electricity, Heat, Light, etc., must be 
occasionally employed, and we therefore place in this 
Introduction, such definitions and brief explanations, as 
may render such terms, when afterwards employed, suf- 
ficiently intelligible. 

GENERAL PROPERTIES OF MATTER. 

Impenetrability. — The power of occupying space exclu- 
sively, or so that another portion of matter cannot at the 
same time exist in the same place. 

Extension, Bulk or Volume. — The amount of space occu- 
pied by any substance, expressed in some unit, arbitrarily 
established. See Appendix, page 283. 

(9) 



10 MECHANICAL FORCES. 

Figure. — The outline or boundary of any body, or por- 
tion of matter. This is generally expressed by certain 
Geometrical terms, such as Sphere, Cube, Pyramid, Prism, 
Octohedron, etc. 

Matter is Indestructible. — By this term, we express the 
fact, that no force exists in nature, capable of annihilating 
an atom of matter ; and that, amid all the changes goiog 
on in bodies, by the operation of natural causes and the 
artificial conditions of our experiments, no particle per- 
ishes or ceases to exist, but that which was once in exist- 
ence, may always be found, however changed in its form, 
by a suflBciently thorough search. 

Example. — Gun-cotton ignited, explodes and disap- 
pears, being converted into gas; but if the explosion is 
conducted in an exhausted glass flask, while the cotton 
disappears, the whole apparatus will weigh as much as 
before the explosion : proving that no loss of matter has 
occurred. 

MECHANICAL FORCES. 
Gravitation. 

Gravitation is the force of attraction which exists be- 
tween every atom in the universe and every other atom, 
drawing bodies together with a force, which varies, directly 
with the products of their masses, and inversely with the 
squares of their distances. 

Gravity.— This term is used to express that part of the 
universal gravitation, which exists between the earth and 
bodies near its surface. 

Weight is the numerical expression of the Gravity of 
any body (i. e. the attraction between it and the Earth) 
reduced to some arbitrary unit, as the pound, ton, ounce 
grain, etc. See Appendix, page 287. 

Mass. — By this word we indicate the quantity of matter 
in a body. This is always expressed, relatively, by the 



GRAVITATION. 



]1 



weight. Thus we believe that a body weighing 2 lbs., has 
twice 3 3 much matter in it as a body weighing 1 lb. 

Specific Gravity, or Density. — By this we indicate the 
relative weight of equal volumes or bulks, of different sub- 
stances. Thus, as a cubic inch of iron weighs t times as 
much as a cubic inch of water, we say that their densities 
are as 1 to 1. 

In practice the density of water at a temperature of 60^, 
is assumed as the unit of density for all solids and liquids, 
and air at 60° with the barometer at 30 ins. is the unit for 
gases. When, therefore, we say that the density of iron 
is 1, of mercury 13^, of gold 19, of alcohol .t92, of chlo- 
rine 2.5, and of hydrogen .069, we mean that the first four 
of these bodies are respectively 1,13^, 19 and .192 times as 
heavy as equal bulks of water ; and that the two j^jg^ j^ 
last are respectively 2.5 and .069, or l-14th as 
heavy as equal bulks of air. 

The methods for determining these densities, 
it would be out of place to explain here in full. 
But we may remark briefly, that the density op 
SOLIDS is determined, by finding their loss of 
weight when immersed in water, as is shown in 
the figure, and then dividing the whole weight 
by this loss, which gives the density. Thus, 56 
grains of iron will lose in water 8 grains, then 
66 -^ 8 = T which is the density of iron. 

The Density of Liquids is found directly by providing 
a vessel which will hold a known weight (say 1000 grains) 
of water, filling this with the liquid to be examined, and 
weighing. Thus, a 1000 gr. bottle (see figure) j-jg, g. 
being filled with mercury, weighs 13,500 grs. the 
density of mercury is therefore 13*; the same 
bottle filled with alcohol would have weighed 
192 grs., its density therefore is .792. 






12 



COHESION. 



The density of liquids is also 
in practice frequently deter- 
mined by the Hydrometer. 
Here the liquid to be tested is 
poured into a tall jar (see figure 
3) and a little tube with a di- 
vided scale, etc. (see figure 4) 
is floated in it. The lighter 
the liquid the lower the tube 
will sink, before it displaces 
enough fluid to support its 
weight, and thus by observing 
the degree on the stem to which 
it sinks, and, referring to a table 
carefully prepared, which al- 
ways accompanies the instru- 
ment, the density of the liquid 
may at once be read ofif. 

Hydrometers are sometimes 
used as a rough means of deter- 
mining the amount of some salt, etc. in a solution, 
by its effect on the density. In these cases, the 
tables are often prepared to indicate this fact, and 
make no reference to the density. This, for exam- 
ple, is the case in the Lactometer, the Yinometer, 
the Saccharometer, etc. 

The Density of Guses is determined likewise by 
weighing them in a closed vessel of known capacity, 
with very careful attention to the temperature and 
height of the barometer. 

Cohesion. 

Coliesioil is that force of attraction which exists 
between adjacent particles of matter. E. g. The force 
which holds together the particles of gold, in a sheet of 
gold leaf, or of lead in a bullet, and which will cause various 




^ig. 4. 



COHESION. 



13 




parts of gold leaf firmly pressed Fig- 5. 

together, or two halves of a bullet 
lately cut, to cling with notable te- 
nacity; as may be seen by the ex- 
periment figured in the drawing, 
where two plates of lead, cleaned 
and pressed together, will support a 
large weight, by their cohesion. 

This force varies greatly with dif- 
ferent materials, as may be seen by 

their various strength, tenacity, or 

resistance to rupture. See Appen- 
dix, page 290. 

Adhesion is a term applied to this force, for convenience, 

when it acts between different substances. E. g. Solder 

and Gold, Silver, etc. ; Wood and Glue, and the like. This 

is, however, a name for a class of actions, not for a new or 

different force. 
Capillary Attraction again is 

the name given to that class 

of cohesive actions, where this 

force is exerted between a solid 

of a tubular, laraillar, or porous 

structure, and a liquid, and 

causes a change of level in the 

liquid, where it comes within 

reach of the attraction of the 

solid. Ex. The rising of oil in 

a lamp-wick, of sap in trees, of 

water in the earth, etc. 

The height varies with the 

diameter of the tube and the 

liquid used, as may readily be 

shown by the apparatus. Fig. 6. 
2 



Fig. 6. 




14 



COHESION. 



Fig. 7. 



Diffusion of Liquids or Gases is the action by which 
liquids or gases of different densities will mix with or dis- 
solve in each other, even against gravity. It 
seems a direct result of " capillary cohesion," 
the porous nature of liquids and gases being 
taken into account. E. g. Fill a glass half full 
of oil of vitriol, sugar syrup or the like heavy 
liquid ; pour upon it gently a layer of water ; 
^Sjpw^^^ after a time they will become completely 
mixed. So if the vessels a e connected by a 
fine tube are filled, {a with light hydrogen, 
e with heavy carbonic acid), they will soon 
be found to have completely mingled their 
contents. 

Osmose, indicates a similar interchange in 
liquids, when it takes place through a porous 
membrane, as moist bladder, parchment 
paper, etc. In this case the rate of transfer 
varies greatly in different substances, and 
thus may be made a means of analysis. This 
subject has been extensively studied by Gra- 
ham, and under the title ''Dialysis," is fully 
discussed in several papers. See Franklin Institute, Jour- 
nal, Yol. 44, pp. 181 and 253. 

Transpiration of G-ases indicates the 
same action in the case of aeriform bodies, 
a most striking example of which is fur- 
*- nished by the following experiment. The 
porous cup or battery cell A, is cemented, 
bottom upward with plaster of Paris, in 
the long glass funnel B. The bell jar C 
filled with hydrogen being then placed 
over A, this gas will transpire into the 
interior of A and B, so rapidly as to force 



^wvuWaiHIIlllli'lii 




out the air in a series of bubbles, 



through 



REPULSION. 15 

water placed in the little vessel D, into which dips the end 
of B. The bell jar being then removed, the hydrogen 
which has passed into A, will transpire again into the 
outer air, with such energy, as to raise the water from D, 
to a great height in the funnel tube. 

The wonderful power which some porous bodies, such 
as charcoal, coke, platinum black, etc., possess, of con- 
densing gases, seems closely allied to the above actions, 
and to result like them from cohesive attraction. 

Repulsion. 

Repulsioil is that force of mutual recession, which exists 

between adjacent particles of matter, opposing cohesion, 

and greatly affecting its action in many cases. This force 

is most largely exhibited in gases, and gives to these bodies 




their almost unlimited powers of expansion. Thus, if a 
flask, containing a bubble of air, but otherwise filled with 
water and inverted in a vessel of the same, is placed under 



16 HEAT. 

the receiver of an air-pump, as the atmospheric pressure is 
removed, the bubble will expand, until it fills the whole 
flask. It is this force of " repulsion" which gives to all 
matter its elasticity of volume. It is closely related to 
heat, being, perhaps, another consequence of the same 
cause, i. e. the motion of all material atoms. See page IT. 

Polarity. 

Polarity is that directive force which causes adjacent 
particles of matter to assume definite relative positions. 
Its fullest exhibition is found in the phenomena of crys- 
tallization, but it is the origin of all rigidity of form to be 
found in solid bodies. 

The subject of Crystallography is too extensive to be 
here discussed, and we must confine ourselves to a few 
references and general statements. 

By reason of polarity, the particles of solids (and those 
of liquids and gases, when about to assume the solid form) 
strive to aiTange themselves in definite directions as 
regards each other, thus forming lines, parallel or inclined ; 
plates, and solids of geometric forms, as cubes, prisms, 
octohedrons, and the like. 

Examples of this action are furnished in the snow crys- 
tals, frost markings on window-panes, and the action of a 
slowly evaporating solution of common salt, etc. 

In many cases this polarity opposes cohesion, and thus 
produces a strain in the crystallized body, which gives it a 
power of affecting light in a remarkable way. See page 69. 

HEAT. 

Heat is the name by which we indicate the cause of a 
sensation experienced when we approach a fire ; and of 
certain effects, expansion, fusion, etc., commonly observed 
to be connected with the same. This cause, we have now 
every reason to believe, is simply a motion, greater or less, 
among the particles of bodies. In other words, the par- 



HEAT. 17 

tides of a hot body are moving more rapidly than those 
of a cold one, and from this more rapid motion, come all 
the properties by which hot substances are distinguished 
from cold ones. These rapid vibrations, communicated by 
contact to the hand, affect the nerves of touch with the 
"tingling" sensation called "heat." When this motion of 
particles becomes more rapid, it causes them to pass 
through greater distances, to push each other apart, and 
to strike with greater force against the sides of a contain- 
ing vessel ; hence arise the phenomena of expansion. 

This rapid motion in solid particles, increasing, may at 
last throw them beyond the range of the polar force ; so 
making the solid, liquid ; hence fusion. Again, this same 
motion, yet more increasing, and thus causing a still wider 
separation between particles, may drive them apart beyond 
the reach of Cohesion ; so changing the solid or liquid into 
a gas or vapor ; hence vaporization, as in boiling, etc. 

Sources of Heat. — 1st. The Sun, where it is possibly 
maintained by the impact of solid bodies, scattered through 
space, which from time to time must fall in upon the sun. 
The heat from this source, shows certain properties of 
intensity, which indicate a very high temperature in the 
orb from which it proceeds. 

2nd. Mechanical action, Friction, percussion, etc. It 
has been proved by Joule and others, that a given amount 
of mechanical action or motion is capable of producing a 
given amount of heat, however the motion be applied. 
Thus, the force or motion implied in the fall of one pound 
weight, through 1*72 feet, is capable of evolving heat 
enough to raise the temperature of one pound of water one 
degree. This is known as " the equivalent of heat." 

3rd. Electricity, when passing through a resisting me- 
dium. E. g. Lightning, Electric sparks, Electric light, Pla- 
tinum wire, ignited by a current, etc. 
2* 



18 HEAT. 

4th. Chemical combination, including ordinary combus- 
tion. Examples of this are countless ; thus the mixing of 
water with oil of vitriol, or with quicklime, or anhydrous 
sulphate of copper, develops great heat. So all cases of 
combustion. 

The cause of the heat motions in all these cases is 
plain. In the 1st and 2nd, the great mechanical motion is 
converted directly into a series of small reciprocating 
motions or vibrations, i. e, " heat." In the 3rd, the resisted 
force, as it passes through, causes the resisting matter to 
vibrate, besides, in some cases, tearing off particles from 
the solid points between which it moves, so giving them 
also vibratory motion. 

In the 4th, the different particles rushing together to 
unite, in like manner establish vibrations, by a similar 
mechanical action. 

The ANIMAL HEAT generated in the bodies of living 
creatures, is simply one case of the 4th source, as it is pro- 
duced by union of the oxygen absorbed by the blood in 
the lungs, with the effete matter, exhausted tissue, etc., 
found throughout the body. It is simply slow combustion, 
which, together with similar actions, such as the decay of 
wood in the air, has received the name of Eremakatjsis. 



Fig. 10. 



O 




Measurement of Heat. 

Thermometers. — Instruments for measuring 
heat. The air thermometer invented by Sanc- 
torio, in 1626, consists of a glass tube and bulb, 
partly filled with air, dipping into a vessel of 
water. When heated, the air expands and the 
surface of the water falls in the tube ; when 
cooled, the air contracts and the water rises. 
This instrument is delicate, but difficult of ad- 
justment for comparison of results. 



HEAT. 19 

The spirit thermometer, invented by a member of the 
Florentine Academy, consists of a capillary glass tube, 
with a bulb, partly filled with alcohol, otherwise vacuous, 
and hermetically sealed, and having a scale attached, 
divided into degrees, as will be presently described. 

This instrument is much used for very low tempera- 
tures, but is useless above 150° F., as alcohol boils about 
1730 F. 

The mercurial thermometer invented by Reaumur. This 
is exactly like the last, mercury being substituted for alco- 
hol. In order that various instruments may be made to 
accord, two fixed points have been settled upon, the melt- 
ing point of ice, and the boiling point of water. The 
height of the mercury corresponding to these being ascer- 
tained, the space between may then be divided into de- 
grees, according to one of three scales now in use, the 
Fahrenheit, the Centigrade, the Reaumur. The first, F., 
divides the space into 180°, numbering the first 32° and 
the last therefore 212° (32 -f 180 = 212.) 

The second, C, divides it into 100°, numbering the first 
0° and last 100°. 

The third, R., divides it into 80°, numbering the first 0° 
and last 80°. 

To convert degrees of one of these scales into those of 
another, the following formula may be used. 

Cent. = |R. = 6 (F.— 32) 



A table showing at a glance 
the coi-responding degrees, will 
be found in the Appendix, p. 291. 



Reau.= 4 c. = 4 (F. — 32) 
Fahr. = I C. +32 = I R. 4- 32 

Above and below the fixed points, the degrees are 
marked off by simple measurement, and comparison with 
those between. Degrees below the 0° of each scale are 
numbered progressively downwards, and are distinguished 
by the sign minus ; thus the freezing point of mercury is 
— 40° F. 



20 HEAT. 

Specific Heat. — We might suppose that the same amount 
of heat being applied to different bodies would raise them 
all to the same temperature ; but this is not so. From 
the different arrangement of particles in various bodies, 
some require more force than others to develop a given 
velocity of movement. This difference of capacity for 
becoming heated, we call Specific Heat. In expressing it 
relatively, we assume water (which has the greatest of all 
rtodies), as the unit. 

Specific Heat of Solids and Liquids. 

Water 1.0000 

Alcohol, sp. gr. =0.81 0.7000 

Nitric Acid, sp. gr. =1.29895 0.6613 

Wood, in the average 0.4800 

Sulphuric Acid, sp. gr. 1.605 0.3346 

Sweet Oil 0.3096 

Lime 0.2169 

Sulphur 0.2085 

Glass 0.1929 

Cobalt 0.1498 

Iron 0.1098 

Nickel 0.1035 

Copper 0.0940 

Tellurium , 0.0912 

Antimony 0.0507 

Zinc 0.0927 

Tin 0.0475 

Platinum 0.0344 

Bismuth 0.0298 

Mercury 0.0290 

Gold 0.0288 

I^ead 0.0281 

The high specific heat of water is of great value in 
moderating the extremes of temperature and equalizing 
climate in the neighborhood of large masses of water. 
The excess of heat is there absorbed without rendering 
the water proportionately hot, and again emitted, without 
corresponding fall of temperature. 



HEAT. 



21 



Specific heat of Gases and Vapors as compared with equal weight 
of Water. 



Water 1.00000 

Air 0.23741 

Oxygen 0.21751 

Hydrogen 3.40900 

Nitf-ogen 0.24380 

Chlorine 0.12099 

Bromine 0.05552 

Carbonic Acid 0.20246 

Carbonic Oxide 0.24.500 

Nitrous Oxide 0.24470 

Nitric Oxide 0.23173 



Marsh Gas 0.59295 

Ether Vapor 0.47966 

Alcohol Vapor 0.45341 

Olefiant Gas 0.40400 

Sulphurous Acid 0.15531 

Hydrochloric Acid 0.18521 

Sulphuretted Hydrogen 24218 

Ammonia 0.50836 

Turpentine Vapor 0.50610 

Bisulphide of Carbon... 0.15696 



A curious connection between the specific heat of bodies 
and their atomic weights was first announced by Dulong 
and Petit, and has been confirmed by Regnault, namely, 
that the specific heats of elements are inversely as their 
atomic weights ; or that the products of these two quanti- 
ties are constant. According to the experiments of Keg- 
nault, however, this " constant " may vary between 2.95 
and 3.41. 

We should, from this law, conclude that the same 
amount of heat is needed to raise an atom of any element 
through a given number of degrees. 

In compound bodies the same law holds good, except 
that the constant varies with different classes of bodies. 
Thus, for the protoxides it is 5.64, for the sesquioxides 
13.6, for the sulphides 4.92, for the carbonates 10.15, etc. 

Effects of Heat. I. Expansion. — All bodies, with cer- 
tain exceptions to be presently noticed, expand with an 
increase of temperature, and contract with a loss of heat. 
This expansion is, however, very various in diflferent 
bodies, as will appear from the following table : 



HEAT. 



Linear Expansion of Solids between 32° and 212° F. for each degree. 

Copper 0.00001092 

Bronze 0.00001009 

Brass, Cast 0.00001043 



White Glass 0.00000478 

Platinum 0.00000491 

Untempered Steel... 0.00000600 

Cast Iron 0.00000618 

Wrought Iron 0.00000656 

Tempered Steel 0.00000689 

Gold 0.00000815 



Silver 0.00001060 

Tin 0.00001207 

Lead 0.00001850 

Zinc 0.00001633 



Cubic Expansion of Liquids between 32° and 212° for each degree F 



Mercury 000085 

Water 000258 

Sulphuric Acid 000330 

Oil of Turpentine or 

Ether 000380 



Common Oil 000444 

Alcohol or Nitric 

Acid 000633 



Cubic Expansion of Gases oetween 32° and 212° for each degree F. 

Air 0.00203111 

Hydrogen 0.00203766 

Nitrogen 0.00203788 

Sulphurous Acid 0.00203866 



Hydrochloric Acid... 0.00204511 

Cyanogen 0.00204561 

Carbonic Acid 0.00204977 



From this it appears that the expansion of various 
gases is practically the same. 

At temperatures above and below those mentioned in 
the foregoing tables, the rate of expansion varies slightly 
with different substances, increasing with the rise in tem- 
perature, and decreasing with the reverse; but these 
changes are not of sufficient importance to be here dwelt 
upon. 

A great variation is also found at those temperatures 
where the body changes its form, as from liquid to solid ; 
and, in the case of water, this amounts to a reversal of 
the rule. Between the melting point, 32° and 40°, water 
contracts as it grows hotter, so that its maximum density 
is at that point, 1. e. 40° ; growing less by change of tem> 
perature either way. 



HEAT. 23 

The tables above given hold good both ways ; bodies 
contracting when lowered in temperature, just as they 
expand when raised. 

The close equality in expansion of glass and platinum 
is of great value, enabling us in constructing apparatus 
to directly weld or join these substances without risk of 
fracture through change of temperature. 

Applications of expansion and contraction are countless. 
Shrinking tires on wheels, iron wheels on axles, etc. ; draw- 
ing up the falling wall of the Conservatoire des Arts et Me- 
tiers ; compensating pendulums and balance- wheels; ther- 
mometers of all kinds ; testing strength of steam boilers 
easily and safely, by filling full with water, closing all 
valves, attaching pressure guage, and warming ; air en- 
gines, etc. 

Effects of Heat. n. Fusion. — Solid bodies heated 
to a certain point, begin to change their form, and to 
become liquid, excepting, of course, such compounds as 
suffer decomposition before this fusing point is reached. 
The temperature at which this change takes place differs 
greatly with different bodies, but is unchangeable for each, 
except as it is slightly affected by great changes of pres- 
sure. Thus, under pressure of 100 atmospheres, the 
melting point of paraflQne is raised 6'3°, and of spermaceti 
3. go Y rpjjg melting point of ice, however, is lowered 
by pressure, so that it may become liquid under pressure, 
and solidify on the relief of the same. This explains the 
phenomena of "regelation," and the motion of glaciers. 
Sec Tyndall on Heat as a Mode of Motion, page 208. 

The fusing point of different substances will be given 
hereafter, where their various properties are described 
under the head of Chemistry. 

Latent Heat of Liquids. — We observe by experiment 
that a large amount of heat is required to convert a solid 
into a liquid, without producing any effect in changing its 



24 HEAT. 

temperature. Thus, if a pound of ice at 32° is mixed 
with a pound of water at 116°, the ice will be melted, 
and we shall have two pounds of water at 32° ; all the 
additional heat in the water (144°) having been absorbed 
by the ice, without, however, any increase to its tempera- 
ture, but with simply a change in its state. Heat so 
absorbed we call "latent heat." 

This phenomenon should be expected from our theory. 
A certain amount of force, in the shape of heat-motions, 
or vibrations, must be expended in overcoming the polar 
force between the particles, and thus changing the state 
of the body. 

This latent heat varies with different bodies, as will be 
seen from the following table, in which the number shows 
how many degrees, the heat absorbed in fusing the given 
substance, would raise the same after liquefaction. 

Bismuth 22.75 

Sulphur 16.86 

Lead 9.66 

Phosphorus 9.05 

Fusible metal* 8.10 

Mercury 4.93 

This latent or absorbed heat, is absolutely necessary to 
the change of form from solid to liquid ; hence if in any way 
this change is effected without giving this required heat, 
the body will, or must, lose a corresponding amount of its 
own heat or heat motion, having in this case performed 
this work of change, by and at the expense of its own inter- 
nal motive power or heat vibrations, and it must therefore 
fall in temperature. This is the theory of " freezing mix- 
tures." Certain bodies if mingled become liquid, by rea- 
son of certain attractions among their particles, they con- 
sequently absorb heat motions in effecting this change, and 
fall in temperature. Some of these bodies, and the descents 

* 1 Lead, 1 tin, and 4 bismuih. 



Water 142.65 

Nitrate of Soda 112.98 

Zinc 50.63 

Silver 37. 92 

Tin 25.65 

Cadmium 24.58 



HEAT. 



25 



accomplished bj rapidly mixing them, are given in the 
following table. 

Sulphate of Soda 8] ^^„ ^ _ 

XT J u, • A -J . ^ +50° to + 2. 

Hydrochloric Acid 5 j 

Pounded ice or snow 2] ncyo i n 

Common salt IJ 

Sulphate of Soda 3} ^^ 

T^•l ^ ^T-. • A • ] o f + ^^° to —2. 

Dilute Nitric Acid 2j 

Sulphate of Soda 6 

Nitrate of Ammonia ^ Y + 50° to — 14. 

Dilute Nitric Acid 4 



Phosphate of Soda 9] 

Dilute Nitric Acid 4 | + 50° to -20. 

Such preparations as the above are often used ; in chem- 
ical operations, where a very low temperature is required, 
as in preparing liquid sulphurous acid, in surgery, and in 
culinary processes, as in the preparation of ice-cream. In 
all cases the more finely the ingredients are pulverized, 
and the more thoroughly they are mixed, the lower the 
temperature reached. It must also be remembered that 
the fluid obtained, is far colder than the solids employed, 
and is indeed the efficient source of refrigeration and must 
not therefore be drained oflF or allowed to escape, until it 
has done its work. 

Freezing. Congelation. — As we might naturally expect, 
when the action last discussed is reversed, and heat is 
abstracted from a liquid, it will at a certain point, begin to 
change its form and become solid. We might also sup- 
pose that the point at which this change took place, in any 
substance, was the same either way. This is indeed so as 
a rule, but not under all conditions. Thus, if water, de- 
prived of air, is kept absolutely at rest, it may be cooled 
to 11° without freezing; then, the least shock or jar, will 
cause it to freeze in an instant. So a concentrated hot 



26 HEAT. 

solution of sulphate of soda, cooled at rest and out of con- 
tact with air, remains liquid indefinitely, until shaken or 
exposed to the atmosphere. 

In becoming solid, the liquid develops as much heat as 
it abstracted in becoming liquid ; this is shown in the case 
of the water by the immediate rise in temperature of the 
whole material to 32°, on the freezing of part, and in the 
ease of the sulphate of soda, by a notable heating. 

In all ordinary cases, moreover, we find that while we 
are freezing or solidifying any liquid, its temperature does 
not fall, during the whole process, though heat is being 
abstracted from it at a rapid rate. 

Expansion in Freezing. — At the moment of passing from 
the liquid to the solid state, most substances expand. This 
is very notable in water, which increases to 1.0Y5 times 
its bulk at 40° ; hence ice floats on water. This expan- 
sion takes place with such force as to burst even strong 
iron vessels, and, under very heavy pressure restraining 
this expansion, according to M. Mousson, water will not 
entirely solidify. 

Like water, cast-iron, antimony and bismuth, expand in 
solidifying ; mercury, phosphorus, stearine, etc., contract. 

Effects of Heat. III. Vaporization. — Liquids when 
heated to a certain point, begin to change their state, and 
to pass into the condition of gases. The temperature at 
which this change takes place, differs greatly with differ- 
ent substances, though it is the same for the same body, 
under the same conditions ; but it is largely affected by 
changes of pressure, the nature of the containing vessel, 
etc. The phenomenon alluded to, is commonly called boil- 
ing, and the temperature at which this action begins, is 
called the ''boiling point." The boiling points of various 
bodies will be stated hereafter, in connection with their 
other properties. 



HEAT. 27 

The effect of a change in pressure, on the boiling point 
of water, will be seen from the following table. 

Water, boiling in the open air, is under a pressure of 
about 15 lbs. per sq. inch (or such as would be given by a 
column of mercury 30 inches high), due to the weight of 
the atmosphere. Under this condition its boiling point is 
212° F. 

Its boiling 
point is 

0. 098 lbs. pr. sq. in. = 0. 006 atmospheres 32° 

= 0.017 " 60° 

= 0.033 " 80° 

= 0.062 ** 100° 

= 0.247 " 150° 

== 0.505 " 180O 

= 1.000 " 2120 

= 2. ** 251.6° 

= 3. ** 276.4° 

= 4. " 295.6° 

= 5. " 311.2° 

= 6. " 324.3° 

== 7. «' 335.8° 

= 8. «' 345.8° 

== 9. " 355.0° 

=10. " 363.4° 

=12. " 378.4° 

=20. «♦ 420,3° 

=40. " 487.0° 

=66.6 " 548.0= 

From this table^ various conclusions may be drawn. 
The boiling point varies less and less with the pressure, 
as it ascends. Thus, the change of less than one atmos- 
phere makes a difference of 180° in the boiling point 
between 32° and 212°, while it makes a change of but 39° 
between 212° and 251°, and of but 25° between 251° and 
216°, etc. These points of pressure and temperature being 
inseparable, one may serve as a measure of the other. 



Under pressure of 






0. 200 ins. of mercury = 


0.098 


0.524 


= 


0.257 


1.000 


= 


0.490 


1.860 


= 


0.911 


.7420 


= 


3.636 


15.150 


= 


7.420 


80.000 


= 


14.700 


61.200 


= 


30. 


91.800 


= 


45. 


122.400 


= 


60. 


153 000 


= 


75. 


183.600 


= 


90. 


214.200 


= 


105. 


244.8 


= 


120. 


275.4 


= 


135. 


306.0 


= 


150. 


387.2 


= 


180. 


612.0 


= 


300. 


1223.0 


= 


600. 


203S. 


= 


1000. 



f' 






HEAT. 



Fig. 11. 



A liqaid inclosed in a tight vessel, will generate a pres- 
sure corresponding to its temperature. If in any way 
this pressure is relieved, the liquid will boil violently, 
because heated above its boiling point for this lesser pres- 
sure. This is well illustrated by the Culinary Paradox. 
Here a glass, containing water in 
the act of boiling, is corked and in- 
verted. If now cold water is poured 
yCC \i{^^ •'•i''''i I <^^®^ t^® flask, the vapor or steam 
('^^kJlr^^^^^^ contained will be condensed, the 
pressure thus relieved, and the water 
made to boil violently. The same 
thing is proved by various experi- 
ments in freezing by evaporation, to 
be presently described. This fact is 
again usefully applied in the manu- 
facture of sugar. 

The pressure of the atmosphere 
varies at different heights ; this ef- 
fects the boiling point of water, and thus' we may, with 
a thermometer, measure the height of various locations. 
A change in boiling point of 1° indicates a change in 
height of 600 feet. On Mt. Blanc water boils at 183°, 
and at Quito at 194°. 

For tension of various vapors at different temperatures, 
see Regnault's Tables, Fr. Inst. Jour., Vol. XY., pp. 136, 
207, 278, 356, and 437 ; Vol. XYL, pp. 48, 115, 186, 257, 
328, and 388; Yol. XYIL, p. 50, 114, and 190 ; Yol. XL., 
p. 241. 

The change in volume which accompanies the change 
of a liquid to the gaseous form, is very great, varying, 
however, with the pressure; the volume of- steam," like 
that of any other gas, varying inversely with the pressure 
applied. At the ordinary atmospheric pressure, however, 
water expands 1694 times in becoming steam. In round 




HEAT. 29 

numbers, a cubic inch of water makes a cubic foot of 
steam. 

The nature of the vessel containing the liquid, has a 
marked effect upon its boiling. A vessel oflfering strong 
adhesion to the liquid, and no points from which bubbles 
of steam can be readily disengaged, raises the boiling 
point, and renders that action violent and spasmodic. 
Thus, water in a smooth and clean glass flask, may be 
raised to 222° before it boils. 

A few scraps of metal, or even angular bits of glass, 
will lower the boiling point to its normal state, and mode- 
rate the violence of the action. 

Water deprived of air, boils also with difficulty and vio- 
lence. In fact. Grove, from many experiments, concludes 
that if water could be entirely deprived of all gas (a re- 
sult never yet attained), it would not boil till heated hot 
enough to cause its decomposition. See Proceedings of 
the Royal Institution, 1864, p. 166. 

Latent Heat of Gases. — As in the conversion of solids 
into liquids, so also in the conversion of liquids into 
gases, we observe that a large amount of heat is ex- 
pended in effecting this change, without any influence 
upon the temperature of the body in question. This fact 
likewise accords with our theory, as before. The lost or 
latent heat is but so much heat-motion expended in over- 
coming the cohesive force, which kept the body in its 
liquid form. 

The latent heat of different gases or vapors, varies 
greatly, that of water or steam being the highest. Thus, 
the heat required to convert one pound of water into 
steam, would raise a pound of water otherwise through 
912 degrees. With other bodies it is as in the table. 



Water 972. 

Alcohol 374, 

Acetic Acid 183. 

3* 



Ether 162. 

•Turpentine 133. 



30 



HEAT, 



Where differences of pressure are introduced, the latent 
heat varies, decreasing with the increase of pressure, and 
consequent rise of the boiling point. 

As we have already noticed with the latent heat of 
liquids, so with gases, if the change of state is accom- 
plished without a supply of extraneous heat, heat must 
be supplied and lost by the changing body itself. We 
may regard the liquid particles as possessing motions or 
heat vibrations, tending to throw them beyond the range 
of cohesion, but not yet sufficiently powerful to overcome 
that force. Hence, they vibrate within their boundaries 
like a pendulum, restrained, but without loss of motion, 
thus preserving their temperature. If now a little addi- 
tional force is given them, just enough (with what they 
possessed) to overcome cohesion, they break their bounds, 
but, in doing so, have spent their force, and (like a pen- 
dulum which has just been able to break from its sup- 
port) fall motionless, or nearly so, into their new state. 
In other words, lose much of their heat motion and be- 
come "cold." All cooling or freezing by evaporation is 
of this kind. A striking instance is as follows : 

If a little water in a small dish is supported over a 
larger one containing oil of vitriol, both being under the 
exhausted receiver of an air-pump ; the boiling point of 
the water will be so low, under the diminished pressure, 
that this action will go on at the 
ordinary temperature, and (the va- 
por formed being absorbed by the 
oil of vitriol) will continue. But 
the water, passing into vapor, 
destroys or renders latent much 
heat motion, it therefore becomes 
cold, and cools the water from 
which it rises, until finally the 
latter is frozen by its own evaporation. We may thus 



Fig. 12. 




HEAT. 



31 



have the strange anomaly, of water, at once boiling and 
fr-eezing, practically realized. 

On the same principle operates the Cryopherous of 
Wollaston, consisting of two connected bulbs containing 
some water, and exhausted of air. All the water being 
turned into one bulb, and the other placed in a freezing 
mixture ; the vapor within is thus condensed as fast as it 
forms, and the water from which it rises is quickly frozen, 
as before, by its own evaporation. 

A more practical application of the same general prin- 
ciple, is furnished in the freezing apparatus of Carr^. 

Fig. 13. 




This consists of two strong wrought-iron vessels, A and 
B,* connected by a tube C, the whole exhausted, and 
closed air-tight. A contains strong aqua ammonia, and 
is placed in a furnace, where it is heated until a thermom- 
eter, set in an oil tube D, indicates a temperature of 
270° F., B, in the meantime, being immersed in water at 
the ordinary temperature. By this means the ammonia 
is driven out of the water in A, and is condensed under 
a pressure of 65 atmospheres into a liquid form in B. A 

* B. is shown in section. 



32 HEAT. 

is then removed from the furnace and plunged into the 
water which before surrounded B, while the vessel con- 
taining the substance to be frozen is placed in the opening 
in B, a little alcohol being poured into the space between to 
prevent it from freezing fast. The pressure being relieved 
by the cooling of A, the condensed ammonia in B boils, 
and its vapor being rapidly absorbed in the now cold 
water in A, this action is kept up, causing a rapid loss 
of heat in B. With the small apparatus sold in Paris for 
100 francs, the heating occupies about 30 minutes, after 
w^hich, with care, two cans full of water (about 2 quarts) 
may be frozen into solid ice. This apparatus may be 
applied to domestic uses. On the large scale it has been 
so constructed as to be continuous in its action, and has 
been reported upon favorably by the French Academy. 
See Journal of the Franklin Institute of Pennsylvania, 
Yol. 48, page 109. 

Evaporation is the term by which we designate the 
gradual vaporization of a liquid at its surface, which may 
take place at any temperature. Example, Drying of a 
wet cloth. This action, like vaporization, implies a great 
absorption of latent heat. Thus masses of water are but 
little affected by the heat of summer, and the body in 
like manner by the evaporation of perspiration from its 
surface is saved from an injurious elevation of its tempera- 
ture, even when exposed to intense heat. Thus Dr. 
Fordice, Sir Joseph Banks, and others, sat for half an 
hour in an oven with a joint of meat which was cooked 
during the time. 

Condensation. —When the action described in vapori- 
zation is reversed, and the temperature of a gas is 
lowered, a point may at last be reached, at which it will 
change its state, and become liquid. This change of a 
gas into a liquid by loss of heat is called Condensation : 
when assisted by pressure, it is termed Liquefaction 



HEAT. 33 

The temperature at which this change takes place is 
identical with that at which the reverse change happens, 
in each substance ; in fact its boiling point, and as might 
be expected, the latent heat expended in the reverse 
change is redeveloped in this. Thus a pound of steam, 
at 212^, would give out in passing into the state of water, 
at the same temperature, as much heat as would raise a 
pound of water through 9*72°, or 912 pounds of water 
through 1°. 

Distillation. — By combining the two processes of vapo- 
rization and condensation, we may effect the separation 
of substances having different boiling points, when these 
are mixed. This operation is called distillation. We 
place the mixture in a closed vessel called a retort or 
still, and there heat it, until the more volatile body is 
vaporized; the vapor formed is carried directly into a 
condenser, receiver, worm, or the like, where it is cooled, 
and so rendered liquid. The more volatile body is thus 
separated from that which is less so, and which remains 
in the retort or still, not being heated to its boiling point. 
It must be remembered, however, that the less volatile 
body will, in these conditions, evaporate, and that thus 
portions will pass over with the other. A complete 
separation cannot, therefore, be thus obtained. Alcohol 
will, for example, carry over with it at least fifteen per 
cent, of water, and mercury a notable quantity of gold, 
even, as well as other metals. 

Sublimation is the term applied to a like action, when the 
substance treated is a solid, which passes into the gaseous 
state, directly or after fusion, and likewise back into the 
solid form. Example, purifying sulphur, iodine, etc. 

Transfer of Heat. — Heat may pass from place to place, 
and body to body, in one or other of three ways, i. e., by 
Conduction, Convection, or Radiation. 

Conduction is the transfer of heat by means of particlos 



34 



HEAT. 



in contact. E. g. The end of a poker being put in the 
fire, the handle will, in time, become heated, by conduc- 
tion, through the iron itself. This power of conduction 
belongs chiefly to solids, and varies greatly in different 
substances, as will appear from the following table : 

Table of conducting powers of Solids. 



Gold 1,000 

Silver 973 

Copper 898 

Iron 374 

Zinc 363 



Tin 303.9 

Lead 179.6 

Marble 23.6 

Porcelain 14.2 

Clay 11.4 



Fig. 14. 



From this it follows, that whenever we wish to pro- 
mote the transfer of heat, we should use good conductors, 
as in culinary vessels, steam boilers, and the like ; while 
for the prevention of this transfer, bad conductors should 
be employed, as in ice-houses, winter clothing, handles of 
tea-kettles, etc. 

Condnction takes place with great dif- 
ficulty IN LIQUIDS. Thus, if an air ther- 
mometer is placed in a liquid, as in the 
drawing, and this is strongly heated at 
the surface, by a hot iron, very little 
effect will be produced upon the ther- 
mometer, at a short distance below. 

The conducting power of gases is pro- 
bably even less than that of liquids, 
though owing to their great mobility and 
diathermancy, this is hard to demonstrate 
directly. The efficiency of double sashes, 
double walls, in iron furnaces, and the 
like, however practically indicates this, 
as does also the following phenomenon. 

The spheroidal state. — By this term we indicate the 
condition of a liquid, when thrown upon a solid body, 
heated considerably above the boiling point of the former; 




HEAT. 35 

when it is lifted out of contact with the solid, by vapor 
first formed, and then remains floating upon this cushion 
of steam, which is supplied as it escapes, by evaporation 
at the lower surface, and protects the liquid from any 
great accession of heat, so that this is never 
raised to its boiling point. This is well shown 
by dropping water over an inverted red-hot 
platinum dish, properly focussed in a magic 
lantern, and watching the image on a screen. 
If liquid sulphurous acid is employed, water 
may be frozen in a red-hot crucible ; or with 
solid carbonic acid and ether, mercury even can 
be frozen in the same situation. The non-con- 
ducting state of the vapor is clearly necessary 
to the above condition. 

By reason of this same action, the hand is pro- 
tected if placed for a moment in a stream of 
molten iron, gold, or the like ; the skin being 
shielded by a non-conducting layer of vapor from the burn- 
ing fluid. This fact explains some conjurers feats, and 
many of the famous ordeals. 

For the production of this spheroidal state, a certain 
temperature is required ; hence the value of the test ap- 
plied by the laundress to her flat-irons. If the water runs 
ofl^ in drops without boiling, the iron is hot enough. 

Convection. — This term describes the transfer of heat 
by particles in motion — as thus: Heat being applied to 
the bottom of a vessel of water, the lower particles of 
the fluid become hot, are consequently dilated, and giving 
place to cold, and therefore denser particles rise, carrying 
their heat into other parts of the vessel. 

This mode of transfer can only exist in liquids and gases, 
^ hose particles are mobile, and is in fact the means by 
which masses of such bodies become heated through- 
out. The currents thus established are easilv shown 




36 



HEAT. 




in water, by a little powdered amber mixed in the 
liquid, and in air by smoke or dust. 

Fig. 16. In all cases of heating such sub- 

stances on the large scale, as in steam 
boilers, house furnaces, etc., it is very 
important that the tendencies of 
these currents should be studied, 
and their maintenance and regularity 
carefully provided for. To such cur- 
rents we owe the draught of chimneys, 
the ventilation of buildings, the trade, 
and other winds, many great ocean 
currents, etc. 

Radiation. — By this term we indi- 
cate the transfer of heat, by motions 
of the nature of undulations, or vibrations, in a certain 
mobile fluid, pervading all space, called the luminiferous 
aether. This impalpable fluid or gas is incapable of any 
direct physical test, but is believed (for the very strongest 
indirect reasons) to exist, and to be not only the vehicle 
of heat, but that also of light, whence its name lumi- 
niferous, or "light bearing." A hot and cold body 
placed at a distance in a vacuum, will rapidly become 
equalized in temperature ; the one gaining, the other 
losing heat. We suppose, in this case, that the motions 
of the hot body have communicated vibrations to the 
aether, which this has in turn conveyed to the colder. 
Heat propagated by this means is reflected, refracted, 
absorbed, polarized, etc., exactly as is light, and may, in 
fact, be regarded simply as slowly moving (in the sense 
of vibrating) light. This, however, will be more fully 
discussed. 

Radiant heat is best reflected by planished surfaces of 
metal, and best absorbed by dull, rough surfaces, such as 
lampblack. It is also absorbed in very difi"erent degrees, 



LIGHT. 3t 

by gases and vapors, and by certain solids and liquids. 
This absorption varies, however, with the character of 
the radiant heat, as regards its intensity, heat from hot 
iron at 500° passing where that from water at 200° would 
not. 

Rock salt is the most " diathermanous^^ solid known, and 
offers equally little resistance to heat of all intensities. 
It is by radiation that the sun's heat reaches us, or that 
of a fire, before which we stand, etc. 



LIGHT. 

By tlie word Light we indicate the cause of that sen- 
sation, affecting the eye, when it is turned upon the sun, 
stars, a burning body, or the like. 

This cause, we have every reason to believe, is identical 
in its nature with heat ; that is, we believe it to be simply 
a very rapid vibratory movement among the particles of 
ordinary matter, and the luminiferous aether already men- 
tioned, which pervades all space, and most bodies (and 
which, though too rare and fine to admit of any direct 
measurement or physical testing) is yet abundantly 
capable of producing those phenomena which we attribute 
to its agency. In fact, the conclusions which these phe- 
nomena themselves lead us to draw, respecting its light- 
ness and mobility, forbid us to expect that, with the 
rough means at our disposal, we should be able in any 
direct way to test or examine it. 

The difference between heat and light consists simply in 
the rapidity of the motions or vibrations producing them. 
If these number between 450 billions and 780 billions per 
second, they constitute light: if less than the first, they 
are heat: if more than the last, they are actinism. 
See page 54. 

Sources of Light. — As might be expected from our theory, 
4 



38 



LIGHT. 



all sources of heat are, or may become, if intensified, 
sources of light. Thus we have, 1st, the Sun. 2nd. Me- 
chanical action. E. g. Flint struck in a vacuum, Perkins^ 
iron wheel revolving 6000 times a minute, and touched 
with a steel file, Fig. 17. 3rd. Electricity. E. g. Sparks, 

lightninsr, aurora, elec- 



Fig. 17. 




trie light, glowing 
wire, etc. 4th. In- 
tense chemical action. 
E. g. Combination of 
iron and sulphur, phos- 
phorus and iodine, 
ordinary combustion, 
etc. 5th. Phosphores- 
cence. E. g. Glow- 
worms, fire-flies, etc. 
In all these cases the 
"light vibrations " are 
developed exactly as those of heat — by the same actions. 

Propagation of Light. — Light emanates from all 
luminous bodies in straight lines, radiating from every 
luminous point. It passes without loss or change through 
free space, but is variously acted upon, and changed in 
its direction and character when traversing different 
bodies. These changes we shall study in their order 
presently. 

The Velocity of Light in free space is 190,000 miles 
per second. This Roemer proved by observation of the 
eclipses of Jupiter's first satellite, in 1675, and Foucault 
demonstrated experimentally with a 
very ingenious apparatus, by which 
he was able to prove that the velocity 
of light was less in water and dense 
media, than in air and other rare 
ones. Since light is projected in 



Fig. 18. 





LIGHT. 39 

straight lines, an opaque body, placed before a source of 
light, will cut off its rays from a certain space. This 
space, so deprived of light, we call the shadow. Thus, A, 
Fig. 18, being a source of light, and B C an opaque body, the 
indefinite space, B C E D, is 
its shadow. If the source ^^^' ^^' 

of light is a point, or at a 
vast distance from B C, this 
shadow will be definitely 
bounded by B D and C E ; 
but if the source of light con- 
sists of many points, or an 
extended surface, A B, Fig. 19, then there will be a full 
shadow, C D E F, where no light enters, and around this 
as penumbra, or gradually decreasing shade, G C E, and 
F D H, from which is excluded the light of some 
only, among the luminous points in A B. 

Interference. 

Though, as a general rule, rays of light, like sounds, 
may cross each other in all directions, without any inter- 
ference or mutual disturbance, yet in certain cases inter- 
ferences may occur. Thus, if two rays are brought 
together in such a way that the rising phase in the 
vibrations or waves of one, corresponds with the sinking 
phase of the other, their opposite motions will be mutually 
destructive; the light motion will cease, and the light will 
disappear. Two rays of light may thus unite to produce 
darkness. If, however, the two waves of light coincide 
in phase of motion, a double brightness is the result. 
This action has the most exact parallel in sound, and in 
undulations of liquids, etc. Thus, an opening like figure 
20 being made between two rooms, a sound produced in 
one of them will not be heard in the other, unless one of 
the two openings, cd, is closed ; because the sound waves 



40 



LIGHT. 



coming through the two passages, and meeting in different 
phases, effect a mutual destruction.'*' We shall have fre- 
quent cause to refer to this subject of interference. 




But at present we shall confine ourselves to one case. 
Two adjacent cones of light, proceeding, for example, 
from two pinholes near together in a card, produce on a 
screen, at a short distance, a series of dark and light 
bands in homogeneous and colored fringes in mixed or 
white light. 

Diffraction. — By this term we indicate the effect pro- 
duced on light, in passing across the edge of an opaque 
body. In this case a new system of undulations is 
developed in the aether, having the solid edge as their 
centre. These, by their interference with the original 
rays, produce fringes of light and darkness (or color with 
mixed light) within and without the geometric shadow 
of the solid edge. Wires, gratings, etc., act in the sa^me 
way. 

* The two rooms are at a and b. 



LIGHT. 



41 



Fig. 21. 



Reflection. — When a ray of light falls upon a polisLed 
surface, it is thrown off again at an angle the same as 
that of its incidence. This may 
be well shown as follows : The 
mirror, M, being so adjusted 
that a ray of light from any 
source is thrown down through 
a diaphragm, N, upon a pol- 
ished horizontal surface, n; 
this ray will be reflected up- 
ward, and will fall upon the 
little movable screen, P, when 
this is so adjusted, as to make 
the angle A n P equal to the 
angle A n N. From this it 
follows, that parallel rays, fall- 
ing on a plane polished surface, 
are reflected in parallel lines 
(see Fig. 22), and that diverging rays are reflected with 




Fig. 22. 



Fig. 23. 




the same divergence as before, the only change being, 
that they now seem to diverge from a point as far below 
the reflecting surface as their actual source is above it. 
(See Fig. 23). 

If, therefore, we are not aware of the reflecting surface, 
we may suppose the light to come, not from its true 
source, but from this supposed or equivalent source, 
behind the reflecting surface. 

This principle has been applied in Dr. Pepper's theatri- 
4* 



42 



LIGHT. 



cal arrangement for "the ghost." A large sheet of plate 
glass, A B, without silvering, is fixed near the front of 




the stage. The "ghost," brightly illuminated by a lime- 
light, is placed at C D, and the rays of light passing from 
this figure through the trap door, C B, and reflected from 
A B, enter the eyes of the audience at 0, just as if they 
came from a similar figure standing on the stage at E T. 
The mirror may also be placed at an angle across the 
stage, and the " ghost " reflected from behind one of the 
wings. 

If the reflecting surface is curved, parallel rays falling 
upon it at different places, will make with it difi'erent 
angles, and, hence, will be reflected in dif- 
ferent directions. 

If the reflecting surface is of parabolic 
form, then parallel rays falling on it will 
be reflected to one point, called its focus, 
and reciprocally a source of light being 
placed in this focus, its rays are all 
thrown out in parallel lines. 

The reflecting power of different bodies 
is very various, and changes with the angle of the inci- 
dent light. Transparent bodies, such as glass, at certain 
angles, allow part of the light to be transmitted, and part 



Fig. 25. 




LIGHT. 



43 



to be reflected. This last increases with the obliquity un 
til a certain point is reached, called the angle of total re- 
flection, when all is reflected, and the body is, as it were, 
absolutely opaque. 

The following table illustrates the relative reflecting 
power of a few substances at different angles. 

The incident light making angles with the surface of 



60° to 90» 



Water 

Glass (Ist surface) 

Black Marble, polished 
Mercury as on Mirrors 



5° 


15° 


30° 


72 


21 


6.5 


54 


30 


11.2 


60 


15.6 


5.1 


70 


15.6 


5.1 



1.8 
2.5 

2.a 

60. 



Unpolished surfaces, by reason of their minute, invisi- 
ble, but countless irregularities, reflect the light they 
receive in all directions ; or, in other words, disperse it, 
thus becoming, in this respect, similar to luminous bodies. 
Part of the light received is of course, however, absorbed, 
even if the body is white ; and if it is colored, it must 
absorb all those colors which it does not give back. Thus, 
a red body absorbs all the colors but red, a green one aU 
but green. 

When the reflecting surface is corrugated very finely, 
as is the case with mother of pearl, fine rulings on glass, 
etc., the reflected rays from adjacent ridges (being very 
little separated), will interfere and produce (in mixed or 
white light), colored fringes, or, as it is called, "m- 
descencey All visible, non-luminous objects also reflect 
light, but from extreme irregularity of surface, presenting 
all angles to the incident ray, they throw it off in all 
dire'^'tions, like luminous bodies. 

Reflection will not only take place at the surface of a 
dense medium, but also of a rare one. Thus, an object 
may be seen reflected from below a surface of water, 
where we may regard the air as the reflecting surface 



i4 



LIGHT. 



(see Fig. 26), or from the rear surface of a plate of glass, 
where the same is true. So, also, a ray of light, passing 

Fig. 26. 




■iiiiiiiiiiiiiiiiiiii!miiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii»^^ 

out with a vein of flowing water, will be reflected back 
and forth from the interior surface of the water, thus fol- 
lowing the stream and illuminating it, and seeming to 
bubble up where the stream breaks. 

By an extensive application of this principle, the beau- 
tiful experiment of the illuminated fountain is arranged, 
the jets being lit up by two powerful lime or electric lan- 
terns, one immediately below, and the other directly 
above them. 

If light falls obliquely on a very thin plate, as in a soap 
bubble, film of oil on water, etc., the rays 
reflected from the first and second sur- 
faces, may interfere, being very little 
apart (see Fig. 27), and thus produce, 
with mixed or white light, colors depend- 
ent upon the thickness of the film, as will 
be explained further on. The rays which pass through 

will also sufi'er interference 
from those twice reflected 
within the plate, so giving us 
the same effect by transmit- 
ted, as by reflected light. 
The film may be of a rare 
substance, as air inclosed be- 



Fig. 27. 




Fio-. 28. 




LIGHT. 45 

tween two plates of glass. If this air film varies in 
thickness regularly around a centre, as when it is pro 
duced by placing a lens upon a plate of glass it will de- 
velop, with white light, concentric rings of color. These 
are known as Newton's rings. The apparatus for produc- 
ing them is shown at Fig. 28. 

Refraction. — A ray of light, coming obliquely upon the 
surface of a body more or less dense than that through 
which it was before passing, is bent from its course, and. 
passes on in a new direction. This bending is called 
refraction. 

Where the ray passes from a rare to a dense body, it is 
bent inward towards the latter; in 
passing from dense to rare this is re- 
versed. In other words, the path of 
the ray would be the same whichever 
way it went ; or if it passes through a 
dense or rare body with parallel faces, 
it will simply be displaced, not changed 
in its direction. (See Fig. 29.) If the opposite sides of 
the body were not parallel, however, ^. ^^ 

its direction would be changed (see 
Fig- 30). ^^ ^ 

The amount of this bending differs 
with different bodies, and also with the angles of the 
incident rays. The relative refracting powers of differ- 
ent substances, are indicated by certain numbers, called 
"INDICES OP REFRACTION." Thcsc are determined by 
experiment. See Table. 

Table of Indices of Refraction. — Solids. 



Fig 


29. 

4 


X)\ 


\c 




Chromate of Lead... 2.50 to 2.97 

Diamond 2.47 to 2,75 

rhosphorus 2.224 

Glass of Antimony. 2.216 
Native Sulphur 2.115 



Zircon 1.95 

Borate of Lead 1.866 

Carbonate of Lead.. 1.81 to 2.08 

Ruby 1.779 

Felspar 1.7G4 



46 



LIGHT. 



Tmrmaline 1.668 

Topaz, colorless .... 1.610 

Beryl 1.598 

Emerald 1.585 

Flint-glass 1.57 to 1.58 

Quartz 1.547 

Rock Salt 1.545 

Rosin 1.543 

Sugar 1.535 

Phosphoric Acid ... 1.544 

Sulphate of Copper 1.53 to 1.55 

Citric Acid 1.527 

Nitre 1.514 



Spermaceti 1.503 

Crown Glass 1.500 

Sulphate of Potash 1.509 

Sulphate of Iron 1.494 

Tallow, Wax 1.492 

Sulphate of Magnesia 1.488 

Iceland Spar 1.654 

Obsidian 1.488 

Gum Arabic 1.476 

Borax 1.475 

Alum 1.465 

Fluor-spar 1.436 

Ice 1.310 



Liquids. 



Bisulphide of Carbon 1.678 

Oil of Cassia 1.631 

Oil of Bitter Almonds 1.603 

Canada Balsam 1.528 

" Linseed 1.485 

** Naphtha, rapeseed 1.475 

Olive 1.470 

'* Turpentine 1.470 

*' Almond 1.469 

♦' Lavender 1.467 

Sulphuric Acid, 1-7 1.429 



Nitric Acid, 1-48 .... 




1.410 


Sol. Caustic Potash, 


1.41. 


. 1.405 


Hydrochloric Acid... 




. 1.410 


Sol. of Common Salt 




1.575 


Alcohol, rectified 




1.372 


Sulphuric Ether 




1.358 


Sol. of Alum 




1 356 


Blood 




1 354 


Albumen, White of Egg... 


1.351 


Distilled Vinegar 





1.372 


Water 




1.336 



Gases. 



Air 1.000294 

Oxygen 1.000272 

Hydrogen 1.000138 

Nitrogen 1.000300 

Chlorine 1.000772 

Nitrous Oxide 1.000503 

Nitric Oxide 1.000303 

Ammonia 1.000385 

Sulphuretted Hydrogen 1.000644 



Hydrochloric Acid 1.000449 

Carbonic Oxide 1.000340 

Carbonic Acid 1.000449 

Cyanogen 1.000834 

defiant Gas 1.000678 

Marsh Gas 1.000443 

Hydrochloric Ether 1.001095 

Sulphuric Ether 1.900153 

Sulphide of Carbon 1.000150 



LIGHT. 



4T 



Fig. 31. 




Fis. .32. 



To obtain the actual refraction for a given ray by a 
given substance, we have this 
rule. The sine of the angle of 
the ray after refraction, equals 
the sine of the angle of the in- 
cident ray divided by the refrac- 
tive index of the body in ques- 
tion. Thus, suppose an inci- 
dent ray, A B, whose sine is 
C D, then the sine, G 0, of the angle, E B G, which the 
ray makes after entering the dense body, X Y, is equal 
to C D divided by the index of refraction of X Y. 

Thus, if X Y is flint-glass, 0G=CD--1.6 thisbeingthe 
index of refraction of this substance. We have already 
seen, that if the opposite surfaces of a refracting medium 
are not parallel, the direction of a ray 
passing through will be changed. 
(Fig. 29.) It is moreover evident 
that if these surfaces, one or both, 
are curved, the rays falling upon 

them will be more or less converged towards a point, or 
diverged and scattered, according 
as the curve or curves are convex 
or concave. See figures 32, 33 
and 34. If now all these curves 
should be elliptical, the following re- 
sults would be accurately attained. 

Parallel rays falling upon a convex 
•lens would all be converged and collected at a certain point 
0, Fig. 35, which is called Fig. 34. 

the " FOCUS." The distance 
C O is called the " focal 
DISTANCE." This is fixed 
for the same lens, but dif- 
fers with the material and 



33. 





48 



LIGHT. 



Fig. 35. 




curvature of different lenses. We can roughly determine 
this for any lens, by holding it 
up at some distance from a 
window, and finding how far 
from it a sheet of paper must 
be held, to receive a sharp 
image of the same. This will 
be the focal distance. 

If instead of parallel we have 
divergent rays coming upon 
the lens, say from C, outside of the focus 0', they can- 
not, of course, be collected 
Fig- 36. at so near a point as 0, 

but yet will be centered 
at some more distant one 
C. If C comes nearer 
to 0', Q' will be further 
off from 0. These points 
C and C are called -'conjugate foci," and of course admit 
of an infinite variety of values in the same lens, though 
always having a fixed inverse relation to each other. If 
corresponded with O', the rays would emerge from 
the lens parallel, and thus have no focus. If C were 
inside of 0', the emerging rays would diverge. A con- 
cave lens reverses all the actions of a convex one. 
formation of Images by Lenses. — Again, if rays from 

Fig. 37. 





points not in the line C C, such as P and come upon 
the lens A B, they will be focussed at certain points P' 



LIGHT. 



49 



and 0', bearing the same relation to P and that C 
does to C. We shall thus have an image formed at 0' 
P' of luminous or illuminated object, differing in size, as 
the conjugate foci differ in distance from the lens. So 
that a small object, brought near to the lens, will make a 
large image at a distance, while a large body at a dis- 
tance will make a small image close to the lens. E. g. 
For the first, the solar or gas microscope and magic 
lantern ; for the last, the camera obscura. The image, 
as we see, will be inverted. This image may be again 
magnified by another lens placed beyond 0' P', Fig. 37. 

Spherical Aberration. — All that we have said would be 
strictly true of lenses whose curves are elliptical or hyper- 
bolic ; but in practice such lenses cannot be constructed ; 
their curves must be spherical. Now with spherical lenses 
the rays passing through the edges are more refracted than 
those traversing the central portion, and are therefore fo- 
cussed at a nearer point. Hence, the clear image, C D, made 
by the central rays would be obscured by the scattered light, 
P, from the edges, 

and likewise with Fig. 38. 

the image of the 
border rays. With 
a single spherical 
lens we cannot ob- 
tain a perfectly sharp 
image, owing to this, 
which is called ''spherical aberration." 

By the combination, however, 
of two or more lenses of different 
curvature, this difficulty is over- 
come. For details, see Brew- 
ster's optics. We have the fol- 
lowing forms of lenses in common 
use: A, Piano convex; B, Piano 
5 





50 LIGHT. 

concave; C, Double convex; D, Double concave; E, 
Meniscus. 

Double Refraction. — When a transparent solid is sub- 
jected to pressure or strain in one direction, it splits or sepa- 
rates an incident raj into two, one of these being refracted 
according to the laws already expressed, the other in a dif- 
ferent direction and degree. The first is called the " ordi' 
nary ;^^ the second the ''extraordinary ray^ Many 
crystalline and other bodies possess the same properties, 
owing to the molecular strain generated in them by the 
crystalline force. Among these the most remarkable is 
Iceland Spar, carbonate of lime crystallized in oblique 
rhombohedric prisms. These crystals 
have two obtuse and six acute solid angles, 
a line joining the obtuse angles is called 
the AXIS of the crystal. In this direction 
alone it has no double refraction, any 
plane parallel to this axis is called a 
"PRINCIPAL SECTION," as A X B Y. In 
every other it separates the rays in a most complete 
manner, so that a line seen through a moderate thickness 
of this substance appears double. We shall return to 
this property under the head of "polarized light." 

Though Iceland Spar alone possesses the property of 
double refraction in so great a degree as to be at once 
evident to mere casual observation, a multitude of other 
bodies have the same power in much lower degree. 
Thus quartz may be made to show a double image, if 
formed into a prism, as will be presently explained. So 
also with glass under pressure ; by combining many 
prisms, a double image may be obtained. Except, in- 
deed, for the mechanical difficulties, similar treatment 
would develop like results in nearly all crystalline bodies, 
except those of the "monometric" system, i.e., cubes, 
octohedrons, and their deriv-atives, in most animal and 




LIGHT 



51 




vegetable fibres, shells, scales, granules, etc., and even in 
some liquids. By certain effects, however, resulting from 
this double refraction, hereafter to be described, its exist- 
ence in all these bodies is easily, though indirectly de- 
monstrated. To develop double refraction strongly in 
quartz, we cut two prisms from a crystal in such a way 
that in A B C E D the axis of the 
crystal is in the direction A B, and 
in B C F G D E parallel to G F, 
and cement their oblique faces 
together. A ray then entering the 
surface A D E I at right angles, 
suffers no change until it reaches 
the surface D E C B at X, when 
it is separated by double refraction, aided by the obliquity 
of the prism, into two rays, X P and X Q. This appa- 
ratus is called the Prism of Rochon. A similar prism may 
be made of Iceland Spar, or we may use simply a single 
prism of that substance, correcting its chromatic aberration, 
by a compensating prism of glass. Such a " double image 
prism," as it is called, will give an enormous separation 
to the two rays, or images. 
See Appendix, page 294 To 
show the double image with 
compressed glass, a system 
of prisms is arranged, as in 
the drawing, so that A B C D 

project and suffer compression from plates of metal forced 
against their ends. The intermediate prisms, R M N, 
etc., not pressed, serve to correct in the ray passed from 
R to T, all deviation, dispersion, etc., except that double 
refraction produced by the pressure. 

Compositionof White Light— We have heretofore spoken 
of light as if it were all of one kind ; a simple motion of 
a definite sort. Every thing we have said would indot^d 




52 



LIGHT. 



Fig. 43. 



be strictly true, say of pure yellow light, such as is pro- 
duced by burning alcohol and salt; but would require 
certain limitations if applied to white light, which is what 
we generally understand by the unlimited noun "light." 
This light is far from being simple ; and we will now pro- 
ceed to study its nature. 

If a ray of light, passing through 

a narrow opening or slit, is al- 
lowed to fall upon a refracting 
prism whose axis is parallel to 
this opening, it will of course be 
refracted or bent from its course ; 
but instead of producing a single 
line of light upon a screen placed in its path, it will 
develop a broad band, in which all the colors of the 
rainbow will be found beautifully blended. It would 
thus appear that, in the ray of white light were all these 
colors. 
This decomposition of white light may be strikingly shown 




Fig. 44. 




LIGHT. 



53 




as follows. (See Fg. 44.) We place Fig. 45. 

as an object, in an ordinary magic- 
lantern, B, arranged for the lime- 
light, a plate of brass having an 
opening in it i of an inch wide, 
shaped like a rainbow, with 3 
inches span. This being properly 
*'focussed" on a screen, say at a 
distance of 50 feet, the lantern 
should be tilted up, as shown in 
the drawing, and a prism held as 
indicated by the figure, in front of 
its object lens. The arch of light 
will then be depressed by refrac- 
tion to the proper place on the 
screen, and broken by dispersion 
into all the prismatic or rainbow 

hues. The prism for this experiment should be made by 
grinding a glass bottle into the shape shown, figure 45, 
cementing plates of glass on the open sides with the 
mixture of molasses and glue used by printers to make their 
*'inking-rollers," and filling it with bisulphide of carbon. 

We know on general mathematical principles, that the 
more rapid the vibrations in a ray, the more it ought to 
be refracted ; and we therefore conclude that white light 
consists of not one only, but many kinds of motions ; the 
slowest of which, separated from the others as at R, is 
recognized as red light, while the most rapid is seen as 
violet atY; and all others arrange themselves in gradual 
progression as indicated in the plate facing page 123. 

Nor does our experiment stop here. By the use of deli- 
cate thermometric apparatus, (see page 121) we find that be- 
low R, Fig. 43, intense heat is present, gradually fading off 
as we descend ; while a sensitive photographic plate or 
fluoresent screen will inform us, that above V, (for a distance 



54 LIGHT. 

more than five times as great as R Y, if an electric light 
and lenses and prisms of quartz are used,) there is spread 
an influence which, though invisible, acts most powerfully 
in effecting photo-chemical decomposition, and may even 
become perceptible to the eye through the influence of 
fluoresent action, this we call actinism. 

The variegated band or ribbon of light thus obtained is 
called a "spectrum." If sunlight is used in this experi- 
ment, and the spectrum, in place of being projected upon 
a screen, is examined through a telescope into which it is 
thrown, countless fine black lines will be seen crossing 
the band, which from their discoverer are called Fraun- 
hofer's lines. Passing over their cause, to be hereafter 
discussed, we at present notice only that they are abso- 
lutely fixed with reference to the colors of the spectrum, 
and their relative places in its length ; and being sharp 
and well defined, are of the greatest use with regard to 
all purposes of measurement. (See plate.) The most 
prominent of these are marked upon the plate, and desig- 
nated by the letters which have always been used to 
describe them. If by another inverted prism or lens, or 
otherwise, these colors are united, they produce w^hite 
light again. It is customary to speak of the colors con- 
tained in white light and constituting the spectrum, as seven 
in number: Ked, Orange, Yellow, Green, Blue, Indigo, 
andYiolet; or as 3 primary colors: Red, Yellow, and 
Blue, with the various tints which would be developed 
by their combination ; as Green composed of Yellow and 
Blue, Yiolet of Red and Blue, and Orange of Red and 
Yellow. In this case, regarding the spectrum as being 
made of three graduated spectra, one of red, one of yel- 
low, and one of blue light, which, variously overlying 
each other, produce all the blended tints. 

Complementary colors are such a pair as would, united, 
make white. One of these at least must therefore be a 



LIGHT. 



55 



compound color. Thus, red and green, yellow and violet, 
blue and orange, are complementary colors. We ought, 
however, to remember that the above ideas are adopted 
merely for convenience ; and that every tint is as truly a 
distinct thing, as each note in a musical scale. Tliat each 
tint of color represents simply so many vibrations per 
second. 



Lengths of Undulations and Numbers per Second. 





Lengths in parts 
of an inch. 


Number in 
an inch. 


Number per second. 


Line B 

Line C 


.00002708 
.00002583 
.00002441 
.00002319 
.00002295 
.00002172 
.00002072 
.00002016 
.00001909 
.00001870 
.00001768 
.00001G89 
.00001665 
.00001547 


86.918 
38.719 
40.949 
48.123 
43.567 
46034 
48.286 
49.609 
52.479 
53.472 
56.569 
59.205 
60.044 
64.631 


451,000,000,000,000 
473,000,000,000,000 
500,000,000,000,000 
527,000,000,000,000 
632,000,000,000,000 
562,000,000,000,000 
590.000,000,000,000 
606,000,000,000,000 
611.000,000 000 000 


Middle Red 

Line D 


Middle Orange... 
Yellow... 

Line E 

Middle green 

Line F 


Middle blue 

** indigo 

Line G 


65.^,000,000,000,000 
691,000.000,000,000 
723,000.000 000.000 


Middle violet 

Line H 


733.000.000,000,000 
789.000,000,000,000 



Spectrum Analysis. 
We find that certain bodies, when vaporized in a flame, 
communicate to it definite colors; as sodium, yellow; stron- 
tium, red ; barium, green, etc. ; and we naturally conclude 
that the particles of these bodies are capable of vibrating 
at certain rates, corresponding to these colors, and at no 
others. This supposition is most completely confirmed. 
If we look at the spectrum produced by a flame otherwise 
non-luminous (as of alcohol, a Bunsen burner, etc.\ in 
which sodium is introduced, we shall see, in place of the 
rich band of various colors, simply a single sharpl}^ defined 
yellow line (see plate facing page 123, Na.) ; showing that 



OD LIGHT. 

all the vibrations here present, are of exactly one velocity. 
Strontium, in like conditions giving a purplish red light 
will show us some red lines and one bright blue (see plate 
facing 123, Sr. ;) so with other bodies, especially the metals. 
The amount of the material needed to produce these 
effects, is extremely small ; and we at once see that we 
have here a most useful and wonderful means of chemical 
analysis for some bodies. 

We provide ourselves with a Spectroscope, which con- 
sists essentially of a narrow slit or opening, a prism, and 
telescope to examine the spectrum, and a Bunsen burner 
with a stand supporting a loop of platinum wire. We 
then fasten the substance to be examined in the platinum 
wire, support it in the flame of the burner, and examine 
the spectrum of this flame with the spectroscope. The 
lines we then see, tell us at once of the presence of certain 
substances, and the lines we miss, of the absence of others ; 
due allowance being made for certain effects of combina- 
tion, which we have not here space to discuss. 

Absorption Bands 

To produce the bright lines above mentioned, the heated 
body must be in the state of vapor ; a highly heated solid, 
gives out rays of all velocities, and hence produces a con- 
tinuous spectrum. But if this mixed or white light — this 
harmony of various notes — passes through such a vapor, 
capable of but one or two rates of motion, the rays of 
-the white light which correspond with these, communicate 
all their motion to the vapor particles, and so lose the 
power of further onward propagation. Thus, a ray of 
white light, which has traversed such a vapor, will have 
lost just those motions which the vapor itself would pro- 
duce ; and if resolved into a spectrum, will show blank 
spaces, that is in fact dark lines, where these rays should 
have been. 



LIGHT. 57 

This may be proved experimentally ia a most direct 
and striking manner (see Tyndall, on Heat, p. 42t) ; and 
furnishes us at once with a means of accounting for the 
Frauenhofer lines. (This was first pointed out by Bunsen 
and Kirehhoff). An. de Chem. et Phy. T. 68. p. 5. 

The sun's light proceeds from within his atmosphere. 
This atmosphere consists of incandescent vapors. Each 
substance in this vapor abstracts certain vibrations, and 
produces certain blank spaces, or dark lines., in the spec- 
trum. By comparing these dark lines with the bright 
lines of vaporized bodies, we may determine what ma- 
terials are found in the solar atmosphere ; and thus reach 
the grand idea of analyzing an orb 95 millions of miles 
distant. We conclude, in fact, that the principal solar 
lines indicate, as above, certain bodies in his atmosphere, 
as follows: 



B 


indicates 


Potassium. 


C 


" 


Hydrogen. 


D 


(( 


Sodium. 


E 


(( 


Iron. 


b 


** 


Iron and Magnesium. 


P 


(( 


^Strontium (?), Iron, and Hydrogen. 


G 


(( 


Iron. 


H 


(( 


Calcium. 



We also recognize chromium, nickel, and possibly, zinc, 
cobalt, and manganese ; but find no indications of lithium, 
copper, or silver. 

This process has been also applied to many fixed stars 
and nebulae, and has shown us that some of these last 
(even those which have been resolved; as the dumb-bell, 
that in sword-handle of Orion, etc.,) are not star clusters, 
but gaseous bodies ; since they give three bright lines, and 
not continuous spectra. (See Journal of the Franklin 
Institute, Vol. 49, p. 422). 

Vaporized bodies, however, do not alone possess this 
power of absorption. Many, or all gases, at ordinary 



58 



LIGHT 



temperatures, liquids, and solids, act in a similar manner; 
and the study of these absorption bands has opened a 
new field to chemical research. (See Journal of Chemical 
Society, 1864, Yol. 2., pp. 59, 304.) Reference will be made 
from time to time to these matters, under the heads of 
the various substances which have special relation thereto. 
Fluorescence. — When light vibrations of very great 
rapidity, such as belong to actinism rather than to light, 
fall upon certain bodies, they cause them to vibrate, but 
with less velocity, so that visible rays are thrown off from 
them in place of the actinic ones which they have received. 
Thus, if the spectrum, made with lenses and prisms of 
quartz from the electric light, is caused to fall on a sheet 
of paper coated with a solution of sulphate of quinine in 
water containing tartaric acid, a long band, above the 
part generally luminous, will be seen to glow with pearly 
blue light. This light contains dark bands analagous to 
the Frauenhofer lines. A great number of substances 
possess this power ; canary-colored glass, extract of sun- 
flower, of horse-chestnut bark, of chlorophyl, of turmeric, 
nitrate of uranium, and the natural phosphate of the 
same, as also a phosphate prepared in a peculiar manner 
to resemble the native phosphate. But none act in so 
striking a manner as quinine and 
canary glass. 

The light best fitted to develop 
these effects, is that obtained by the 
electric discharge in a vacuum, and 
no experiment in physics can exceed 
in beauty that which is seen when 
the discharge of a Ruhrakorff coil is 
caused to flow from the tinfoil lining 
of a canary goblet, over its edge to 
the pump plate, under an exhausted 
^jljlil bell-jar. We then have u goblet of lu- 



Fig. 46. 




LIGHT. 



59 



miaous emerald, filled with fire, from which pink, purple, and 

blue streams pour over on every side, and drip at every part. 

A very beautiful effect is also produced by passing the 



Fig. 47. 



discharge through an exhausted 
electric egg of this same glass, 
and figures, painted on a screen 
with quinine, entirely invisible by 
ordinary light, become luminous 
in the dark by the light of the 
"aurora tube" (Fig. 79). 

Phosphorescence. 

When these reverberations or 
secondary vibrations of light are 
very persistent, and last for 
some moments after the cause of 
them has ceased to act (resem- 
bling the resounding of a sonorous 
body, as a bell after it has been 
struck) ; we call the phenomenon 
Phosphorescence, not, however, 
using this term in the same sense 
as when it is employed in connec- 
tion with the body Phosphorus, 
which, in this sense, is not phos- 
phorescent. 

Sulphides of calcium and stron- 
tium, exhibit this action in the 
most prominent manner. Such 
bodies, exposed to a strong light, 
and then removed to a dark place, 
continue to glow visibly for some time. The same 
effect is also very beautifully shown in some Geisslor 
tubes, which continue to emit light after the discharge in 
them has ceased. 




60 



LIGHT. 



This is noticed in the form shown at A B, in Fig. 80. 

Dispersive Power is the term applied to that property 
of unequally refracting the different colors, by which the 
prismatic spectrum, and other similar effects, are pro- 
duced. This power varies with different bodies, as may 
be seen from the followinor table : 



Table of 

Oil of Cassia 0.139 

Sulphur after Fusion 0.130 

Phosphorus 0.128 

Sulphuret of Carbon 0.115 

Balsam of Tolu 0.103 

Balsam of Peru 0.093 

Oil of Bitter iMmonds 0.079 

Oil of Aniseed 0.077 

Acetate of Lead, fused 0.069 

Guaiacum 0.066 

Oil of Cumin 0.064 

Oil of Tobacco 0.064 

Gum Ammoniac 0.0G3 

Oil of Cloves 0.062 

Oil of Sassafras 0.060 

Rosin 0.057 

Oil of Spearmint 0,054 

Kock Salt 0.053 

Caoutchouc 0.052 

Flint-Glass, 1st sample .... 052 

Oil of Thyme 0.050 

Oil of Caraway Seeds 0.049 

Oil of Juniper... 0.047 

Flint-Glass, 2d sample 0.047 

Nitric Acid 0.045 

Canada Balsam 0.045 

Oil of Rhodium 0.044 

Oil of Poppy 0.044 

Muriatic Acid 0.043 

Gum Copal 0.043 

Nut Oil 0.043 



Dispersive Powers. 



Turpentine 0.042 

Felspar 0.042 

Balsam Capivi 0.041 

Amber 0.041 

Calcareous Spar. 0.040 

Oil of Rape-seed 0.040 

Diamond 0.038 

Olive-oil 0.038 

Gum Mastic 0.038 

Beryl 0.037 

^ther 0.037 

Seleinte 0.037 

Alum 0.036 

Castor-oil 0.036 

Crown-Glass, Green 0.036 

Water , 0.035 

Citric Acid 0.035 

Glass of Borax 0.034 

Crown-Glass 0.033 

Plate-Glass 0.032 

Sulphuric Acid 0.081 

Tartaric Acid 0.030 

Nitre, least refr 0.030 

Borax.: 0.030 

Alcohol 0.029 

Sulphate of Baryta 029 

Rock Crystal 0.026 

Borax Glass (B 1, Quartz 2) 0.026 

Sulphate of Strontia 0.024 

Fluor Spar 0.022 

Cryolite 022 



LIGHT. 61 



Chromatic Aberration.— Its Correction. 

From this difference in dispersive power come some 
important results. 

We readily see that our former statements about lenses 
must be modified with regard to this ; namely, that beside 
other irregularities in the focussing of rays where white 
light is used, the violet rays would come to a focus much 
nearer to the lens than the red, and the other colors at va- 
rious intermediate points ; so that from this cause we would 
have an ill defined image fringed with color which would 
change with the relative position of the screen object and 
lens. Thus at Y the im- 
age would have a border '^g- • 
of unfocussed red and 
other rays, and at R of 
violet and other ones. 
This would be a most 
fatal error, but fortunate- 
ly it may be corrected, 
thus : A concave lens would of course reverse all the 
effects of the convex one A, B, and would disperse the 
colors in an opposite direction. Such a lens, if of equal 
curvature, would therefore exactly neutralize the disper- 
sion of A, B ; but then it would also neutraliz(^ the refrac- 
tion, and thus make the lens as useless as a flat plate of 
glass. But if the concave lens were made of a substance 
having a much greater dispersive power than A B.then it 
would neutralize the dispersion, even though of less cur- 
vature, and thus would (Hminish, it is true, but not dati^oy 
the refractive action of A B. In short, it would make it 
a lens of longer focus, and " achromatic," that is without 
color. 

The substance commonly used for this purpose is (lint- 
glass. Combining thus a double convex lens of crown- 
6 




LIGHT. 




Fipr. 50. 



glass, with a plauo concave, or with a meniscus lens of 
flint (there being here two refracting 
curves for the crown, and one for the 
flint, see A B), or by uniting two 
double convex lenses of crown, with 
one double concave of flint, see C D, 
we obtain what are called " achro- 
matic," or " CORRECTED LENSES," which 
are almost free from irregularity of re- 
fraction. It is, however, impossible to find any two 
bodies, whose refractive and dispersive powers so exactly 
correspond as to make an absolute correction. 

Polarized Light. — We have yet another point to con- 
sider about the nature of light. Not only is a ray of 
light composite, in the ways already mentioned, but also 
as regards the plane in which its vibrations 
are moving. Thus, a ray of ordinary light 
may be looked upon as consisting of vari- 
ous series of undulations, moving in every 
possible plane containing its line of direc- 
tion. The cross section of such a ray 
would be represented by Figure 50, the 
radial lines indicating the planes in which 
the particles were vibrating. By various means we may 
so modify and " sift out" these vibrations, 
as to obtain a ray in which all are in 
parallel planes, so that its section would 
be represented by figure 51, the parallel 
straight lines representing the planes in 
which the particles are vibrating. 
Plane Polarized Light is that in which 
all the vibrations are in parallel planes, at right angles to 
the direction of the ray. 

This plane polarized light (the word plane is often 





LIGHT. 



63 



Fig. 52. 




omitted for brevity) may be obtained from ordinary light, 
in one of the three ways following : 

1st. By reflection and transmission. If a ray of light 
falls upon a transparent reflecting body, such as water or 
glass, at a certain angle, differing with the substance, it will 
be partly reflected, and partly transmitted ; both parts will 
be polarized more or less entirely, the one transmitted, 
in a plane perpendicular to the 
surface of the reflector, and the 
reflected one at right angles to 
this. The figure will give a 
good idea of this action. We 
here assume only two planes 
of motion in the ordinary ray, 
for convenience. In practice, 

of the other vibrations, those nearest one plane go to it, 
and those nearest the other to it ; or escaping, give that 
mixture of ordinary light to our polarized ray, from which 
it is never entirely free. The polarizing angle for Glass 
is 56° 45'; for Water, 52° 45' ; for Quartz, 57° 32'; for 
Diamond, 68° ; and for Obsidian, 56° 30'. 

2nd. By absorption. If a ray of light passes through 
a slice of the mineral tourmaline, which is cut parallel to 
the axis, all its vibrations, except those in one plane, are 
absorbed and destroyed within the crystal, so that the 
emerging ray is polarized. The iodo-sulphate of quinine 
in crystals possesses this same property. 

3rd. By double refraction. 
Whenever a ray suffers double 
refraction, it is also polarized, 
each of the emergent rays being 
polarized in a plane at right an- 
gles to the other. 

Nicoi.'s i*i{i.sM i se»' ])age 50). 
i.^ciaad Spar is the substance used in preparing polarized 



Fis:. 53. 




64 LIGHT. 

light in this way, and since in practice it is desirable to 
get rid of one of the two rays, the crystal is cut in a plane 
passing through its obtuse angles, and again cemented 
together with Canada balsam. By this means the extra- 
ordinary ray, A B, suffers total reflection at the surface 
of the balsam, and is thrown out at the side. This is 
called a Js^icol's Prism. Fig. 53. 

Properties of Plane Polarized LigM. — These may be 
most easily understood and remembered by means of a 
simple physical illustration, which is extremely useful as 
a means of briefly expressing the facts of the case, though 
in no respect to be regarded as an explanation of their 
final cause. 

Suppose that light rays are so many flat rulers, and 
that polarizing bodies are gratings, whose bars are par- 
allel to the planes in which they transmit polarized light. 
Then an ordinary ray, having its rulers in all positions, 
coming upon one of these gratings, all the rulers are 
"reflected," "absorbed," or " refracted, out of the way," 
except those which are parallel to the bars of the grating, 
and which therefore get through. If now a second grating 
is set beyond, parallel to the first, all the rulers which 
have passed the first will pass it also ; but if this second 
grating is set at right angles to the first, the rulers will 
all be stopped by the two ; for those that passed the first 
are just those which cannot pass the second. 

Thus it is in fact with light. If we place two polarizing 
bodies in the path of a ray, it will pass, if both are par- 
allel, but will be entirely cut ofi" if they are "crossed." 
When two polarizing bodies are used, the one nearest the 
light is called the polarizer, and the other the analyzer. 

Thus Fig. 54 represents an apparatus for developing 
the effects of polarized light. Light falls upon the mirror 
A B from the left. The reflected, polarized ray, which is 
thrown upward, then passes through the tube H H, which 



LIGHT. 



6b 



contains an analyzer, ^jg* 54. 

such as a bundle of 
glass plates placed 
obliquely in the tube. 
If these tast are paral- 
lel to the mirror A B, 
the polarized ray will 
be reflected, and will 
not be seen through 
H H ; but by turning 
this tube H H hori- 
zontally through 90° 
in the socket G G, 
on which it rests, the 
light will be no longer 
reflected, but will be 
transmitted by the 
analyzer, and may be 
seen through H H. 
A rotation, however, 
of 90° more, or 180° 
from the starting 
point, will again bring 
the analyzer into a 
position to reflect all 
the polarized light 
from A B and show 
none of it through liiiii 
H H. 

Objects to be ex- 
amined by polarized 
light, may be placed in the ring F F,, and viewed through 
the analyzer in 11 II. Plates of doubly refracting sub- 
stances, display splendid colors, and sections of crystals, 
the beautiful iris rings to be presently described. 
6-^- 




Fig. 55. 



LIGHT. 

A plate of doubly-refracting substance 
may be regarded as a grating, with two 
systems of openings (Fig. 55) at right 
angles, leading off, however, in different 
directions. 



Colored Effects of Plane Polarized Light. — Suppose a 
ray of ordinary light. A, to fall upon a Nichol's prism, and 

1 „ 6. 





to yield a plane polarized ray, O. If this ray now passes 
through a very thin plate of some doubly refracting body, 
C, placed as represented, the ray will be split into two, 
p' and s'; one of which will be retarded behind the other, 
by the distance of part of a vibration (this depending on 
the nature and thickness of the film) ; but these, being in 
different planes, cannot interfere with each other, though 
they will be so little apart in position as still to be prac- 
tically together. If now these adjacent yet separate rays 
fall on another Nichol's prism, each will again be split, 
and a half of each will be refracted to p' s', while the 
other halves will be thrown out at p" s". Now p' and s' 
will be in the same plane, and capable of interfering. If 
then, white light has been used, and the retardation of 
one ray behind the other amounts to half a red vibration, 
the red vibrations in p' and s' will interfere and destroy 
the red light ; if, however, the retardation was half a red 
vibration, it would be more than half a yellow or blue one; 



LIGHT. 



6t 



Fig. 57. 



hence these waves would not interfere, and we should 
have green light at p' s' by the removal of the rea. If 
the plate C were thinner, or of some other material, the 
retardation would have been less; it then would not have 
destroyed the red, but some other color, and we should 
therefore have something else than green at p' s'. If the 
principal section of the plate C was parallel or perpendic- 
ular to the plane of polarization of the light O, it would 
pass through unchanged, and be transmitted or not by D, 
according as B and C coincided or not. 

If instead of the thin plate C we place a slice, made at 
right angles to the axis, of a double refracting body, in the 
same position, with a diverging beam of polarized light, 
we will have projected on a screen a black or white cross, 
intersecting a system of consecutive 
rainbow-colored rings. (See figure 51.) 
The cause of this may be stated as 
follows : The slice of crystal may be 
regarded as having its doubly re- 
fracting properties arranged about its 
centre ; or, to give it a physical repre- 
sentation, as having openings for the 
passage of rays, in radial and circum- 
ferential directions, as in the figure 58. 
Suppose now the polarized light to be 
vibrating in a vertical plane, its vibra- 
tions will pass through in the line 
M N, and the other radial lines near ^'[i 
this, without change ; so also through 
the parts of the circles near X' Y, 
which are also vertical ; and this light ^ 

will then either be stopped or transmitted by the analyzer 
D, according as that corresponds or is opposite to the 
polarizer B. This will then give the black or white cross. 
A vertical polarized ray, striking at R. will, however, find 




.^vni ^ 



68 



LIGHT. 



Fig. 59. 




Fig. 60, 



no direct passage, but will be split, part going through the 
radial, part by the circular passage. These divided rays 
will be united, and will produce color, as in the case of 
the thin plate before described. Moreover, the divergent 
rays, coming on this plate, will have to 
traverse greater thicknesses the further 
they come from the centre (see figure 
59) ; thence will produce different colors, 
and as these differences will vary con- 
centrically about the axis X, the colors 
will be disposed in rings, intersected by the crosses. 

The best specimen for this experiment is a plate of Ice- 
land spar, about one-twentieth of an inch thick, well pol- 
ished. Such an one, placed as indicated by the drawing 
Fig. 56, in a good gas microscope, with 
a screen about 20 feet off, gives a most 
charming figure, which may be further en- 
hanced by adding to it a plate of quartz, 
similarly cut and about one-tenth of an 
inch thick. 

Some bodies, such as nitre, have two 
axes of no double refraction near to- 
gether. Similar slices from these give 
double systems of rings, crossed by dark 
or light " brushes," produced by union of two crosses. (See 
Fig. 60). Other crystals of two axes, such 
as sugar, aragonite, etc., have these so far 
apart that only one system of rings and 
brush can be seen at a time. (See Fig. 
61.) 

These actions of polarized light are 
used in a variety of ways in chemical 
investigations. The change of color pro- 
duced by polarized light in many bodies, 
crystalline and organic, help us to recognize them; and 




Fi?. 61. 




LIGHT. 69 

the presence of these crosses or colored rings are simi- 
larly useful, besides helping us to study the condition 
of crystalline bodies, in relation to their condition of me- 
chanical strain. 

Blocks of glass, gelatin, etc., strained by pressure or 
sudden heating or cooling, exhibit colored figures, having 

Fig. 62. 




remarkable analogy to those of crystals. These, when 
used in the gas microscope, must have an object-glass in 
front of them, between them and the analyzer. 

Rotation of the Polarized Ray.— If in place of the slice 
of Iceland spar, in the experiment just described, we put 
a similar plate of quartz, cut from a crystal at right angles 
to its axis, we shall have a system of colored rings as 
before, but instead of the cross, black or white, the central 
space will be filled with colored light, which will change, 
as the analyzer D is rotated, through all the colors of the 
spectrum. The reason of this is as follows: This sub- 
stance, though like others it does not produce double re- 
fraction along its axis, etc., does twist the plane of the 
polarized ray, giving its edge, as we may say, the shape 
of a screw-thread. The amount of this twist is. however, 
dififerent for each color. Hence in each position of the 



TO - LIGHT. 

analyzer some colored rays will pass, while others will be 
stopped; thus the colors are produced. 

Some specimens twist the ray in one direction, others ib 
the opposite. Those which so turn it that the colors change 
upward, from red through yellow, green, etc. to violet, 
when the analyzer is rotated over the crystal in the direc- 
tion that watch-hands move over its face, are said to have 
right-hand polarization, or to be dextrogyre ; those that 
change oppositely from violet, through green, etc., to red, 
by the same motion, or similarly to the first by an oppo- 
site motion, are said to have left-hand rotation, or to be 
Isevogyre. 

The amount of this polar rotation varies with different 
bodies, and in the same body with its thickness. 

This power of rotation belongs to other solid bodies 
besides quartz ; to others, as Faraday's heavy glass, it 
may be communicated by magnetic action ; and it also 
exists in some liquids and solutions, as that of cane and 
grape sugar. 

Saccharimeter. — With regard to these substances this 
property is used as a commercial test of value. By means 
of an appropriate apparatus, a given depth of solution, 
containing a known quantity of the sample in question, is 
examined by polarized light, and the amount of rotation 
suffered by a given color being ascertained, we may from 
this estimate the quantity of the corresponding substance 
contained in the solution. Cane sugar has right, and grape 
sugar left-hand rotation. If these are mixed they in part 
neutralize each other's effect; we must, then, after our first 
determination, convert the whole into grape sugar by 
hydrochloric acid, and then, having made a new determi- 
nation, settle by a calculation the original proportion of 
each. This process may be applied to many other sub- 
stances. 



ELECTRICITY. 



1 




Fig. 64. 



Circularly Polarized Light is that in which the vibra- 
tions are in two planes, at right angles to 
each other, but differing also in phase by 
an odd number of quarter-wave lengths. It 
may be produced by passing a ray of plane 
polarized light, through a Fresnel's rhomb 
(Fig. 63), when suffering two total reflec- 
tions at an angle of about 54°, it will issue 
w^ith the properties required for circular po- 
larization. Circularly polarized light may 
also be obtained by Airy's method, if ordinary light is 
made to fall vertically on a film of mica 
or selenite, of such a thickness, that the 
ordinary ray shall be retarded more than 
the extraordinary by the required amount. 

With circularly polarized light the 
images produced by slices of crystals are 
changed, the black cross disappearing, 
and the alternate segments of the rings 
being dislocated. Thus, for Iceland spar, we have the 
Figure 64. 

Elliptically Polarized Light is that in which the vibra- 
tions are in two planes, perpendicular to each other, but 
differing by some quantity, not an exact multiple of quar- 
ter-wave lengths. This is obtained from a Fresnel's rhomb 
if the incident and refracted rays have any other angle 
than 45° between their planes; also if common light is 
reflected from a metallic surface. 




ELECTRICITY. 

We indicate by this term the cause of a certain class of 
phenomena, such as the attraction which amber, etc., pos- 
sesses for light bodies after being rubbed, the lightning 
flash, the decomposition of bodies by a' galvanic apparatus, 
the polar position of a magnet, etc. 



Y2 ELECTRICITY. 

Theory of tlie Double Fluid. — In giving a physical 
explanation of electric phenomena, and connecting them 
in a way convenient for study and reference, we must 
begin by making certain assumptions, which, however, it 
must be remembered, have no other proof than that they 
strvc t( connect and explain the phenomena in question. 

We assume that all space and all mattei* is pervaded by 
two impalpable fluids, alike in general character, but 
having, in certain respects, exactly opposite properties; 
that, for this reason, when mingled in equivalent quanti- 
ties, they entirely neutralize each other, as regards these 
opposing properties, and show no signs of their existence 
(these fluids, together or separately, may perhaps constitute 
that ssther, to which we have before alluded, as serving to 
transfer the vibratory motions, which we recognize as light 
andheat). These opposite electric fluids we designate as 
positive (+), and negative ( — ), and their assumed pro- 
perties may be very briefly stated. 

The particles of each fluid are mutually repellant, but 
attract those of the opposite fluid, and of matter generally. 
They are capable of rapid motion or transfer through some 
bodies, as metals, moist air, etc., but are almost precluded 
from traversing others, as glass, shellac, dry air, etc. They 
may be, 1st, separated and confined in or upon certain 
bodies ; or, 2nd, set in rapid motion in opposite directions ; 
or, 3rd, Caused to form series of currents in the individual 
particles of certain substances. These three conditions 
give rise to three divisions of our subject, Statical Elec- 
tricity, Galvanism, and Magnetism. 

STATICAL ELECTRICITY. 

By this term we indicate that condition of the electric 
fluids in which they are separated more or less completely, 
and confined for a greater or less time, to certain bodies. 

The methods by which this separation may be effected 



ELECTRICITY. 73 

are numerous, but the simplest and most characteristic is 
by friction. 

If two different substances are rubbed upon each other, 
their electric fluids will be more or less separated; an 
excess of the positive fluid collecting in one, and of the 
negative in the other. Experiment : Rub a glass rod with 
a silk handkerchief; bring the rod near a pith-ball suspended 
by a silk thread, the ball will be attracted ; so also will ii 
be by the silk (each fluid in turn attracts the matter of the 
ball). Now touch the ball with the rod, then ball and rod 
will have the same fluid ; hence the ball will now be re- 
pelled by the rod, but will be more powerfully attracted by 
the silk than before (these two have now opposite fluids 
which attract). In this case the glass collects the positive 
fluid, the silk the negative. 

The power of collecting one or the other fluid is not 
positive in certain substances, but simply relative ; the 
body which takes positive and loses negative fluid by friction 
with one substance, will, with another, take negative and 
yield positive. Arranging all substances in their order of 
positive or negative attraction we would have a table like 
the following, in which any substance, rubbed with one 
below it, will take positive fluid, but rubbed with any 
above it will take negative fluid. This is what we mean 
by calling a body electrically positive or negative. 
The bodies at the beginning are, in a general sense, posi- 
tive ; those at the end negative ; but any substance is 
positive to any one below it, and negative to any one 
above. 

Table of some Substances in their Electrical Relations, 
Fur. Paper. 

Smooth glass. Silk. 

Woollen clothe Lac. 

Feathers. Rough glass. 

Wood. Sulphur. 

Gun-cotton and like bodies. 



74 



ELECTRICITY. 



Conductors and Insulators. 

Bodies through which the fluids easily pass are called 
Conductors, those which resist their motion, Non-conduc- 
tors or Insulators. These properties are relative, as we 
may see by the following table, which begins with the 
best conductors, and ends with the worst, which is, there- 
fore, the best insulator. 

In the following list the bodies are arranged in their 
order of conducting power, according to the present state 
of knowledge on the subject, and though probably not 
absolutely correct, it will serve to show how insensibly 
conductors and non-conductors merge into each other: — 



Table showing the Relative Condacting Power of Certain Substances 
for Electricity. 



Metal, best conductor. 

Well-burnt charcoal. 

Plumbago. 

Concentrated acids. 

Powdered charcoal. 

Dilute acids. 

Saline solutions. 

Metallic ores. 

Animal jfluids. 

Sea water. 

Spring water. 

Rain water. 

Ice above 13° Fahr. 

Snow. 

Living vegetables. 

Living animals. 

Flame smoke. 

Steam. 

Salts, soluble in water. 

Rarefied air. 

Vapor of alcohol. 

Vapor of ether. 

Moist earth and stones. 



Powdered glass. 

Flowers of sulphur. 

Dry metallic oxides. 

Oils, the heaviest the best. 

Ashes of vegetable bodies. 

Ashes of animal bodies. 

Many transparent crystals, drj 

Ice below 13° Fahr. 

Phosphorus. 

Lime. 

Dry chalk. 

Native carbonate of bary'es. 

Lycopodium. 

Caoutchouc. 

Camphor. 

Some siliceous and argillaceoua 

stones. 
Dry marble. 
Porcelain. 

Dry vegetable bodies 
Baked wood. 
Dry gases and air. 
Leather. 



ELECTRICITY. 


Parchment. 


Mica. 


Dry paper. 


All vitrifications. 


Feathers. 


Glass. 


Hair. 


Jet. 


Wool. 


Wax. 


Dyed silk. 


Sulphur. 


Bleached silk. 


Resins. 


Raw silk. 


Amber. 


Transparent gems. 


Shellac. 


Diamoad. 


Gutta percha, worst conductor. 



Y5 



The Electrical Machine. 

To eflfect this separation of the fluids with ease, we 
employ an "electrical machine," which consists of a 
glass disk. A, mounted on an axle, and turned by a 
handle, of a " rubber," B, made of leather spread, 
with mosaic gold (bisulphide of tin), and supported on 
a glass column ; of a silk apron, E, of collecting points, 
F, and of a round ended cylinder of metal, G, called 
the *' prime conductor," supported on a glass column. 
The positive electricity, developed in the glass, by fric- 
tion on the rubber, when the former is turned, is car- 
Fig. 65. 




ried round to the points, being protected from escape 
by the apron. At the points it is drawn oflf into the 



T6 ELECrr.TCITY. 

prime conductor, where it collects. The negative elec- 
tricity accumulates in the rubber. To get much positive 
electricity, we must connect the rubber with the earth, by 
some good conductor ; to get much negative, we must in 
like manner connect the prime conductor, insulating of 
course the rubber. 

With this apparatus, many ingenious experiments, illus- 
trating the attractive and repulsive powers of unlike and 
like fluids, may be performed, such as the dancing images, 
the sportsman and birds, the dancing pith balls, the in- 
dustrious spider, the electric flyer, and orrery, etc. 

Hydro-Electric Machine. 

A similar separation of the electric fluids may be 
effected by the friction of steam, containing particles of 
water in suspension, on the sides of peculiarly shaped 
orifices. (See Fig. 66.) In this case 
Fig. 66. the orifices become negative, the issuing 

steam positive. Points placed opposite 
the escaping steam will collect the posi- 
tive fluid. Again, by the dry pile to be 
described hereafter, see page 101, this 
same separation is effected ; and again, 
also, by the Ruhmkorfif coil, which will 
be described, when the necessary pre- 
liminary matters have been discussed. 
(See page lit.) 

Electrical Attraction and Repulsion. 

The first effect of electricity actual!}^ observed, and 
that most likely to excite attention, is the attraction and 
subsequent repulsion of light bodies. The connection of 
these actions with our theory of electricity has been 
already explained, page 72, but the phenomena them- 
selves may be strikingly exhibited by the following pieces 




ELECTRICITY. Tt 

of apparatus and instruments for measurement of electric 
force : 

The chime of bells (Fig. 67) consists of a brass rod, 



Fig. 67. 




A. B, supported by a stand, and connected by a chain or 
wire with an electrical machine. From each end of this 
rod hangs by a chain a metallic bell, wliich thus receives 
electricity from the machine. Near each bell hangs by a 
silk thread a little brass ball or clapper, which is attracted 
by the bell, until it strikes it, when, receiving a charge of 
fluid, it is repelled in turn, but attracted then by a centre 
bell which is suspended by a silk cord fVom the rod, A B, 
and is connected with the ground by a chain. Each 
clapper, as it strikes this bell, therefore gives up its elec- 
7* 



Y8 



ELECTRICITY. 



tricity, aud is then again attracted to the outer bell, so 
that a constant motion and chiming is thus maintained. 

The dancing pith-balls (Fig. 68) exhibit a like action. 
The balls are in this case first attracted by the upper plate, 
touch it, become charged, are repelled; strike the. lower 
plate, so lose their charge, are again attracted, and so on. 

Fig. 69. 




The electrical umbrella (Fig. 69) consists of many strips 
of colored paper connected with a brass rod, which may 
be supported on the prime conductor of an electrical ma- 
chine. These strips, being all similarly excited, repel each 
other, and so stand out like an open umbrella, when the 
machine is in operation. 

On a similar principle is constructed the quadrant elec- 
troscope. In this the brass rod fits into the prime con- 
ductor, and has attached to it a light rod with a pith-ball. 
This being charged similarly to the rod, is repelled from it, 



ELECTRICITY. 



T9 



the amount of its repulsion, measured on a small quadrant, 
indicating the intensity of the charge. 

This is, of course, but a rough instrument ; one far more 
delicate is furnished in the gold-leaf electroscope, Fig. TO. 
Here two strips of gold-leaf (Dutch gold is best) are sus- 
pended from a brass plate, in a glass vessel ; any electric 
fluid passed into them causes them to repel each other, 
and so diverge. 



Fig. 70. 



Fig.. 71. 




A more delicate instrument, of like nature, is seen in 
Coulomb's electrometer. Fig. Yl. In this case a light rod 
of gum shellac carries at one end a pith-ball, and is sup- 
ported by a (ibre of silk, the whole being inclosed in a glass 
vessel ; a small brass ball terminates a wire which enters 



80 ELECTRICITY. * 

this vessel. If this wire, and consequently the brass ball 
is excited, it first attracts the pith-ball, but then, after con- 
tact, repels it, so twisting the silk fibre. The distance to 
which the pith-ball is repelled in this, as in a former case, 
indicating the intensity of the electrical excitement in 
question. 

Distribution of Electricity. 

The electric fluids, when separated as above, always 
reside on the surfaces of bodies. Thus, in non-conductors, 
they cannot penetrate the substance, and being collected 
at the surfaces must remain there; and in conductors, by 
reason of the mutual repulsion of like particles, they are 
forced outward to the surface. Opposite fluids, put in the 
same conductor, would, of course, mingle and neutralize 
each other. By reason of this repulsion, the fluids readily 
collect on and escape from projections and points ; and 
similarly enter a conductor by such points from a sur- 
rounding surcharged medium. 

Thus we terminate all instruments, intended to retain 
electricity, with rounded surfaces, balls, and the like ; but 
use points where we desire to introduce the fluids, as in 
the collecting points, F, Fig. 65, of the electrical machine 
(these points are attached to the brass rods, one of which 
is shown in the drawing, along their iuner sides, and are 
directed towards the glass plate). 

So, again, with lightning rods; these should have 
sharp points, for, if thus provided, and in good connection 
with the ground, they attract and gradually withdraw from 
the approaching thunder-clouds their charges of electricity, 
and thus often prevent a '^flash,^^ as well as divert to a 
safe channel those not to be so obviated. 

That electricity occupies alone the outer surfaces of 
bodies, may again be shown if we provide a hollow metallic 
sphere, with an insulating support and an opening by 



ELECTRICITY. 81 

which its iDterior surface may be reached. Then, when 
the sphere has been charged, electricity may easily be 
obtained from its outer surface by touching it with a ''test 
plane," i. e. a little button or wafer of brass mounted on a 
glass handle ; while none can be obtained by this means 
from the inner surface. The " test-plane," after touching 
the sphere, should be brought in contact with the plate of 
the electroscope. Fig. *rO, when the gold-leaves will diverge, 
if any electricity has been received by the planes. 

Indlictioil of Electricity. — This phenomenon, like the 
last, is the direct, necessary consequence of those general 
properties of the electric fluids, stated at the commence- 
ment of this subject. 

Thus, suppose a conductor charged with positive elec- 
tricity, to approach an insulated conductor in the natural 
state, without touching it. Then the positive fluid in the 
charged conductor will drive the positive fluid in the 
insulated conductor to its further side, and draw the 
negative fluid to the nearer. The fluids would in this 
way be separated in this insulated conductor, so long as 
the charged one remained near it. This mode of sepa- 
rating the fluids we call "induction." It develops some 
curious consequences. 

The Electrophorus. — Suppose we have a shallow pan, 
filled with solid shellac, and excite this negatively by 
friction ; that we then place upon it a plate of brass, 
varnished with shellac, and having a glass handle. The 
lower face of this will become Fig. 72. 

positive, and the upper negative, 
for the reasons just stated. If 
now we connect this with the 
ground for a moment, by touch- 
ing it with the finger, the repel- 
led negative fluid will escape, and jj^ 
some positive will enter to fill 




82 ELECTRICITY. 

the space of that drawn towards the shellac. If this 
plate is now lifted away from the shellac, by its glass 
handle, it will clearly have in it an excess of positive 
fluid, which, being no longer held to one place by an 
attraction, can pass all over it and escape. This action 
can be repeated without loss of electricity to the shellac, 
and thus furnishes a supply of that agent, which admits 
of many ingenious applications, among others the light- 
ing of gas burners, as in the many forms of apparatus 
for that purpose, invented by Robert Cornelius, Esq., of 
Philadelphia. 

The Leyden Jar. — We have already noticed, that the 
electric fluids, by reason of repulsion, reside on the sur- 
faces of conductors, and tend to escape therefrom. Such 
bodies are thus unfit to serve as reservoirs of this agent, 
but by an application of this fertile action of "induction," 
the difi&culty is surmounted. 

We coat a glass jar inside and out, nearly to the top, 
with tinfoil. We close the mouth with a cork or cover 
of wood, through which passes a rod, connected metalli- 
cally with the inner coating. Holding the jar by its outer 
coating in the hand, or otherwise connecting it with the 
ground, we then pass electricity into the inner coating, 
by the rod. As this spreads over the inner coating, it 
drives away a corresponding amount of the same fluid 
from the outer coating, and draws into it an equiva- 
^^^ • lent amount of the opposite, so that the two coat- 
ings become oppositely charged, and these fluids, 
attracting each other, do not tend to escape. This 
apparatus is called the Leyden Jar. 

A number of these having their outer coatings 
united by strips of tinfoil pasted in a box which 
contains them, and their inner coatings united by 
brass rods, form a "battery of Leyden Jars." To use 
tb*^ electricity thus stored, we make such a connectioQ 




ELECTRICITY. 



83 



Fig. 74. 




that it may pass from one to the other coating, through 
the object or apparatus we wish 
it to traverse. 

Transfer of Electricity. — Elec- 
tricity may pass from one body 
to another, by three different 
methods; by conduction, by con- 
vection, and by discharge. 

Conduction is the transfer 
through particles in contact. This 

takes place with different facility, in different bodies, as 
has been already mentioned, see page Y4, and also varies 
with the temperature of the same body, diminishing with 
an increase of heat. Where the size of the conductor is 
sufficient for the quantity of the current to be conveyed, 
no change is produced ; but when the conductor is insuf- 
ficient, and resists the passage of the fluid, heat is 
developed. Thus a large battery being discharged through 
a strip of gold-leaf, placed between two plates of glass, 
melts and vaporizes the gold ; driving it into the glass, 
so as to produce a purplish stain. So w^ith a fine wire 
of iron, or platinum, etc. 

When passing freely through a good conductor, elec 
tricity moves with a velocity of 288,000 miles per second. 
This was measured by Wheatstone, in 1834. (See Philo- 
sophical Transactions for that year, page 589.) 

Convection is the transfer of electricity by motion in 
particles of an interposed fluid, such 
as air. Thus, the air particles touch- 
mg a charged conductor, get the same 
fluid, and are repelled, move off to 
some neutral or oppositely charged 
body and allow others to take their 
piace. These in turn follow the same 
course, a current is established, and 



Fig. 75. 




84 ELECTRICITY. 

the electricitj is thus transferred. This may be well 
shown by attaching a pointed wire to the prime-con- 
ductor of a machine, and holding a burning candle or 
lamp near it. The flame will then be blown aside, if not 
extinguished, by the draft of air. 

Discharge is the simultaneous transfer of electricity 
developed by induction in the particles of an interposed 
non-conductor. Thus, particles ABC etc., in a given 
line' being excited by mutual induction, make a discharge 
when A gives its fluid to B, at the same time that B gives 
its own to G,.and so on. This transfer may be more or 
less resisted, and its character thus modified, by the inter- 
posed substance. We accordingly have two classes of 
discharge, the disruptive discharge, flash, or spark, where 
the fluids pass through a highly resisting medium, and 
the diffused or flame discharge, where the medium ofi'ers 
but slight resistance. Between these there may be every 
possible gradation ; but we may include all cases in one 
or other of these classes, without further division. 

The Disruptive Discharge is seen when the fluids pass 
through the air, as in the ordinary spark from the machine, 
from the Leyden jar, from the induction coil, and in the 
lightning. In all cases it is accompanied by a light and 
sound, both varying in intensity with the amount of elec- 
tricity which is passing. The color of the light varies 
with the points between which, and the medium through 
which, it passes. In all our experiments the spark is ac- 
companied by a transfer of the material of which the 
points are made, and it is only reasonable to conclude 
that the light owes its existence to the vibrations pro- 
duced in these particles, as they are torn ofi* from one 
point and thrown towards the other. 

The sound is caused by the rapid heating and cooling 
of the air in the path of the flash, thus producing in it 
such a vibration as will affect our ears. 



ELECTRICITY. 



85 



Viewed through the spectroscope, the light of this dis- 
charge gives only bright lines, varying with the sub- 
stances, showing that they are in a gaseous state when 
developing this light. (Pro. of Roy. Inst., 1863, p. 47.) 

Many pretty experiments may be made with this dis- 
charge — as the lightning-jar, the lightning-plate, the 
spark-plate, the letter-plate, the luminous profile, the 
lightning-house, etc. 

This spark is capable of igniting many compounds, — 
as gun-cotton, ether, explosive mixture, burning gas, etc. ; 
but will not fire gunpowder, unless it is retarded, as by 
passing through a wet string.* It will also effect many 
chemical changes of combination and decomposition. For 
igniting most of these bodies we place them upon the 
table of the universal discharger, Fig. 76, and then pass 



Fig. 76. 




ll!iilll!llililllillll!illllliiill!!il!'iiPiillllliil!li^^ 



• In this experiment the wet string must be between the powder and 
the negative coating 
8 



86 



ELECTRICITY. 



the spark through by means of the adjustable rods c d f g, 
supported on the glass columns h h. 

Liquids like ether we place in a spoon, and take a spark 
into it by a wire hung from the prime conductor of a ma- 
Fig. 77. 




chine; and for explosive gases, such as a mixture of 
oxygen and hydrogen, we use a little brass cannon (Fig. 
78), having a small brass rod passing through a gla.ss tube 

Fig. 78. 




into it, so that a spark entering this may spring acro»» to 
the body of the cannon inside, so firing the contaipcd 
gases, and driving out a cork placed in the muzzle. 

If an egg be placed upon the table of the universal dis- 
charger. Fig. 76, and the spark from a Leyden jar, or the 
Ruhmkorff coil, be passed through, it will be illuminated 
in a remarkable manner, so as to have the appearance of 
being red-hot. 

Its vitality is of course destroyed, but it is otherwise 
uninjured by this treatment. 



ELECTRICITY. 



8T 



79. 



The Glow Discharge. — This takes place when the inter- 
posed medium offers little resistance to the passage or the 
fluids. This is well seen where the discharge traverses 
rarefied air, gas, or vapor, as in the aurora tube 
(Fig. 7^), where the tall glass tube is exhausted 
by the air-pump, and then has its caps con- 
nected with the poles of a Ruhmkorff coil. 

The color of the discharge in this case is 
chiefly effected by the rarity and nature of the 
interposed medium. This is well illustrated in 
the Geissler tubes (Figs. 80 and 81), which are 
filled with various gases, and then exhausted, 
by means of a mercurial air-pump, to a Torricel- 
lian vacuum, or nearly so, and sealed. If now 
the platinum wires, passing through their ends, 
are connected with the poles of a Ruhmkorff coil, 
streams of beautifully variegated light will fill 
them, crossed by obscure bands. With hydrogen 
this light is chiefly pale purple; with nitrogen 
pink, with a violet-blue glow, filling the negative 
end of the tube, where the wire, entering the 
bulb, will be coated as it were with a layer of 
orange-colored light. Bulbs of Canary glass 
placed within these tubes, as in C D, Fig. 80, 

Fig. 80. 




88 



ELECTRICITY. 



glow like so many emeralds amid the purplish and pink 
light of the discharge. In some cases the exhausted 
tubes, bent into complex forms, are surrounded by other 
tubes, which may be filled with various fluorescent or 
even simply colored solutions. Thus in Fig. 81 we fill 
A C with a solution of quinine and B D with nitrate of 
uranium. We then have the negative ball, say F, full 




of blue light, the part T) C brilliant rose-color, F purplish- 
pink, and the portions within the solutions are bordered 
from A to C with a magnificent blue, and from B to D 
with a rich green color. The single tube G H (Fig. 81) 
is arranged on the same plan. Simple colored solutions, 
such as bichromate of potash and sulphate of copper, may 
be used in place of the fluorescent ones, with equally 



MAGNETISM. 



89 



Fi-. 82. 




beautiful effect. There are few things, if any, within the 
range of philosophical experiments to be 
compared for beauty with these just de- 
scribed. 

If a double barometer (Fig 82) has its 
two mercury columns connected with the 
poles of a "coil," a stream of light will 
pass through the arched vacuum above. 
This light will be white, on account of the 
vapor of mercury present. An absolute 
VACUUM (obtained by placing caustic pot- 
ash in a vessel filled with carbonic acid 
and then exhausted, and allowing the pot- 
ash to absorb the last trace of this gas) is 
totally impervious to the electric dis- 
charge. If, however, the potash is heated 
the discharge will be renewed, the slight 
vapor produced seeming to furnish matter 
sufficient for this action. This same effect 
was observed with the intense water-bat- 
tery of 3520 cells used by Gassiot as well 
as with the coil. (Philosophical Trans- 
actions, 1859, p. 148. 




MAGNETISM. 

Magnetism is that department of electricity which treats 
of the properties of magnets. 

A magnet is a body which has the power of attracting 
iron and some other metals, and of setting itself in a 
definite position with reference to the earth's axis, so that 
one end points toward the north pole. 

According to our theory, a magnet owes these, and its 
other peculiar properties, to the fact that the electric fluids 
8* 



90 



MAGNETISM. 



Fig. 83. 




Fig. 84. 



in its various particles are not at rest, but are flowing in 
opposite directions, malcing a series 
of closed circuits in each particle. 
Regarding for simplicity the positive 
flnid alone, Fig. 83 would indicate 
the condition of a magnet. The 
small spheres representing particles, 
and the arrows showing the direc- 
tions of the currents of positive fluid 
in each. The negative fluid we 
suppose to be forming similar currents in the opposite 
direction. With the direction for the positive current 
indicated in the figure, the front end (to the right) would 
be the South, the other end the North 
pole. These directions being reversed, 
the poles would be reversed also. The 
aggregate effect of all these currents 
would evidently be nearly identical 
with a close spiral around the surface, 
as in Fig. 84. 
Of magnets, we have — natural magnets or loadstones, 
artificial magnets, and electro-magnets. The end of any 
magnet, which turns towards the north, we call its north 
pole, the other the south pole. 

Loadstone. — This is a peculiar ore of iron, being a mix- 
ture of the proto and sesquioxide of iron (FeO-f Fe^Og), 
found abundantly in nature, and possessed of the magnetic 
properties already mentioned. 

Artificial Magnet. — This is a bar or rod of steel, which 
has received magnetic properties by being rubbed with 
another magnet, or placed within a spiral galvanic current. 
Such a magnet will possess all the peculiar properties of 
the natural loadstone, generally in intenser degree. 

These magnets are sometimes made in the shape of 
straight bars, sometimes they are bent into the shape of a 




MAGNETISM. 



91 



horse-shoe or of the letter U. These are called " horse- 
shoe or U MAGNETS." They gradually lose their mag- 
netic properties unless a bar of soft iron is kept across their 
poles as S N, Fig. 85. This bit of iron is called an "arm- 
ature." A magnetic bar made light, and delicately 



Fig. 85. 






MAGNETISM. 



balanced, so as to tarn horizontany about a point, is called 
"a magnetic needle.'''' 

Two such needles, fastened one over the other with re- 
versed poles, form an as- 
Fig. 86. tatic needle, which will 

stand east and west, and 
be deflected by a very fee- 
ble force, see Fig. 86. In 
practice astatic systems 
are so constructed as to 
have one needle more 
powerful than the other; 
they therefore point north 
and south, but can be de- 
flected by very feeble forces. 
With all magnets, like poles repel, opposite poles attract. 

Besides iron, in its va- 
rious forms, magnets 
attract feebly nickel, 
cobalt, and chromium ; 
and very powerful mag- 
nets have also a pecu- 
liar effect on all other 
bodies, causing some to 
arrange themselves Iq 
the line of their poles, 
and others at right an- 
gles to this, see Fig. 87. 
The first are called Magnetic, the second Diamagnetic 
bodies. Among the magnetic substances are salts of iron^ 
even in solution, as also those of chromium and manga- 
nese ; among the diamagnetic are bismuth, antimony, 
phosphorus, most gases, and organic bodies. 

Electro-magnet. — This is a bar of soft iron, around which 
a spiral galvanic current is made to pass, as, for example, 




MAGNETISM. 



93 



in a bobbin of insulated wire. Such 
a body has all the properties of a mag- 
net so long as the current continues, 
but loses them the moment this cur- 
rent ceases. 

In electro-magnets the wire is gene- 
rally wound entirely outside of the iron 
bar ; so that the current produces its 



Fig. 88. 




Fig. 89. 




effect only inwards. A very ingenious modification has 
been made, however, by Mr. Ebon Jayne, in which the 




Fig. 91. 



GALVANISM. 

u'hole influeDce of the current is utilized. In 
this, the coil is wound on a bar of iron which 
forms one pole, while a cylinder of iron, slipped 
over the coil and joined to the bar at one end by 
an iron cap forms the other. See Fig. 90. 



Magnetism by Induction. — Whenever a magnet is 
brought near a bar of iron or steel, it con- 
fers upon it, all magnetic properties. The 
poles of the induced magnet are opposite 
to those of the inducing one. Thus, if the 
horse-shoe magnet, N S, have two iron 
keys brought near it, as in the drawing, 
the keys will be magnetized by induction, 
with poles, as shown in the figure ; and 
nails, in turn brought near to these, w^ould 
be likewise affected. 

If the body once magnetized in this or 
any other way is of steel, it retains its 
magnetic properties, but if it is of wrought iron, it loses 
them, as soon as the magnetizing agency is withdrawn. 




GALVANISM. 

Gralvanism is that department of electrical science which 
treats of the phenomena first pointed out by Galvani and 
Volta, as the result of certain connections of two metals 
and a liquid, and of other actions having a close relation 
to these in cause and character. According to our theory, 
we believe that when two metals are immersed in a liquid 
capable of acting chemically upon one of them, and are 
connected by a good conductor, as the chemical decompo- 
sition of the liquid, which ensues, progresses, the electric 
fluids are separated, and caused to pass in opposite currents 



GALVANISM. 



95 




through the circuit of the materials employed ; the positive 
fluid, going to the metal least 
acted upon, thence through the 
conductor to the other metal, 
and so through the liquid to 
the starting-point again ; the 
negative fluid following, mean- 
while, the same path in the 
opposite direction. 

Such a combination of parts 
is called a galvanic " couple;" 
many of these connected form 
a " BATTERY ;" couplcs of Cer- 
tain forms are called "cells." 
The two metals or their equivalents (for non-metallic 
bodies may in some cases be used) are called " elements ;" 
the one most acted upon being always the positive sub- 
stance (see page 73) ; the other the negative. The posi- 
tive fluid will, however, always come out from the nega- 
tive element. The fluid used is commonly called the 

" EXCITING LIQUID." 

In the following table each substance is negative with 
all above, and positive with all below it, when placed in 
galvanic relation. This order is in some cases, however, 
effected by the nature of the fluid employed. See Phil. 
Transactions, 1840, p. 113. Diluted sulphuric acid is the 
exciting liquid assumed in the table here given : — 

Electro-chemical Order of the Principal Elements. 
Electro-negative. Iodine. 

Oxygen. Phosphorus. 

Sulphur. Arsenicum. 

Selenium Chromium. 

Nitrogen. Vanadium. 

Fluorine. Molybdenum. 

Chlorine. Tungsten. 

Bromine. Boron. 



96 aALVANISM. 


Carbon. 


Cobalt. 


Antimony. 


Nickel. 


Tellurium. 


Iron. 


Titanium 


Zinc. 


Silicon. 


Manganese. 


Hydrogen. 


Uranium. 


Gold. 


Aluminum. 


Platinum. 


Magnesium. 


Palladium. 


Calcium. 


Mercury. 


Strontium. 


Silver. 


Barium. 


Copper. 


Lithium. 


Bismuth, 


Sodium. 


Tin. 


Potassium. 


Lead. 


Electro-positive. 


Cadmium. 





The terminal points of the series, where the connection 
outside of the liquid is not completed, are called the posi- 
tive and negative " poles" or " electrodes," according as 
the positive or negative fluid comes from them. 

Galvanic Batteries. 
Omitting those forms of galvanic batteries which, how- 
ever interesting in an historical connection, are not prac- 
tically useful, and have therefore been abandoned, we will 
describe the forms now generally employed. 

Hare's Calorimeter. 

This consists of two very large spirals of sheet zinc and 
copper, wound together, in close proximity, without con- 
tact. This is accomplished by interposing strips of card- 
board while hammering into shape, these being afterwards 
removed, and the strips sustained and kept in place by 
wooden bars, as indicated in the Figures 93, 94, 95. This 
pair of plates is then immersed in a tub, bucket, or large 
jar of diluted acid, and for a short time will act with won« 
derful energy. The hydrogen, liberated by the decompo- 
sition of the water (whose oxygen goes to the zinc form- 



GALVANISM. 

Fig. 93. 



9t 



Fig. 94. 




ing oxide of zinc, which is then taken up 
by the acid), at once attaches itself to 
the copper-plate in countless bubbles, 
which not only interfere with the con- 
ducting power of the series, but present a positive surface 
in place of the negative copper, thus causing the battery 
rapidly to "run down," or lose strength. 

Smee's Battery. — Tn this each cell consists of a glass 
jar, containing diluted sulphuric acid, in which hang from 
a cross-bar of wood three plates, the middle one of pla- 
tinum, coated with a deposit of the same metal tinely 
9 



98 



GALVANISM. 



divided, to which hydrogen bubbles will not adhere. At 
each side of this hangs an amalgamated zinc plate. 
These two zinc elements are united, so that they act as 
one. In connecting several of these, the zincs of one cup 




are joined by a wire to the platinum of the next, and so 
on. In place of platinum plates leaden ones, coated first 
with silver, and then with platinum black, may be em- 
ployed. This battery is feeble but steady, and may be 
charged and left for a long time without deterioration, if 
the connection is not made between its poles 

Daniel's Battery. — In this each cell consists of a copper 
vessel, containing a solution of sulphate of copper ; within 
this a porous cell or cup of unglazed earthenware, con- 
taining diluted sulphuric acid, in which is immersed a 
cylinder of zinc. The hydrogen liberated in this case 
passes into the sulphate of copper, decomposing it and 
throwing down metallic copper, by combining with the 
oxygen of the oxide of copper in the salt, so forming 
water. This battery, therefore, gives off no gas at all, 
and (some crystals of sulphate of copper being placed on 
a shelf in the outer vessel to restore the solution as it be- 
comes impoverished) is very constant. It is, however, 
feeble, as compared with the following forms. , 



GALVANISM. 



99 



Fi-. 97 



Grrove's Battery. — Tn this each cell consists of an outer 
jar, containing diluted sulphuric acid, in which is set a 
hollow cylinder of zinc ; 
within this is a porous cup, 
filled with strong nitric 
acid, in which hangs a 
slip of platinum foil. The 
hydrogen liberated in this 
case, passing into the nitric 
acid, takes some of its oxy- 
gen from it to form water, 
leaving it as nitric oxide, 
which at first dissolves in 
the acid, and when that is 
saturated escapes in fumes. 
The decomposition of the 
nitric acid developes an in- 
crease of force, which ren- 
ders this the most powerful 
form of constant battery yet 
invented. 




Illllllilllllllllllllllllllllllllllllllllllllllillllllllllllllllll 



Fi*'. OS. 



Bunsen's Battery. — This battery differs from the last 
only in the substitution of solid bars or cylinders of 
" gas-carbon " for the platinum foil. 
This is dictated by economy. The 
best form of this battery for rapid , 
handling is that manufactured by 
Delcuil, of Paris. The cokes are 
hollow cylinders, very porous, and 
connection is made by copper 
plugs, which can be forced into 
the ends of these, and are joined 
to copper strips riveted to the 

zincs Connections can be made and broken by this 
me&ns with greater ease, certainty, and dispatch than 

L.cfC. 




100 GALVANISM. 

with the best form of binding screws ; and this, in the 
management of a large battery, is of great importance. 
For telegraphic purposes, however, the battery made by 
Chester & Co., of New York, is better than this. 

Modified Forms of the Bimsen Battery. — Chester & Co., 
of New York, manufacture a Bunsen battery, which an- 
swers very well for medical applications, in which the 
gas-coke is made into a cup in which the zinc is supported, 
the exciting fluid being a solution of sulphate of mercury. 
This gives off no fume and uses no seriously corrosive 
liquid. Its energy and constancy are increased by addi- 
tion of a little table-salt. An ordinary Bunsen cell will act 
in a similar manner, for a short time, if the porous cell is 
removed, and a solution of glauber salt (NaO,S03) is em- 
ployed as the only exciting liquid. (See Journal of the 
Franklin Institute of Pennsylvania, Yol. 50, p. 68, 1865.) 

Chester & Co. also manufacture another form of the 
same battery, under the title of "electropoion battery." 
The important feature in this is the substitution of a mix- 
ture of sulphuric acid and solution of bichromate of pot- 
ash for the nitric acid. This removes the difficulty of acid 
fumes, and relieves a great expense, the cost of this mix- 
ture being about one-tenth that of nitric acid. A good 
recipe for this mixture is this : in a gallon of water dissolve 
one lb. of bichromate of potash ; to this add two pints of 
oil of vitriol. (See Journal of Franklin Institute, Yol, 50 
page 68.) 

This battery works very well with the Kuhmkorff coil 
and also for the electric light. 

The Iron or Maynooth Battery. — In this, each cell con 
sists of an iron cup, containing a mixture of equal parts 
of nitric and sulphuric acids, within this is a porous cup 
filled with dilute sulphuric acid, and containing a plate of 
amalgamated zinc. Tiie best form of this battery is that 
manufactured by Bullock and Crenshaw, of Philadelnhia, 



GALVANISM. 



101 



iu which the iron cups are rectangular, and the zincs of 
rolled metal. 

This is the cheapest form of battery, and equal, if not 
superior, to any other of equal surface, in effect. 

We must, however, in this connection remark that the 
mixture of strong nitric and sulphuric acids here used 
gives off a most acrid and irritating fume less during the 
action than during the charging and emptying of the 
battery. Arrangements should, therefore, be made for a 
strong draft or current of air to carry these fumes away 
from the operator during this process. The best plan is to 
conduct it in the open air. 

The electro-motive forces of some of the preceding bat- 
teries have been estimated as follows : 



Bunsen element 839 

Grove 829 

Daniel 470 



Smee 
Hare 



210 
208 



Besides those already mentioned, very many other com- 
binations of solids and liquids have been suggested for 
galvanic batteries, but none others have proved in prac- 
tice successful. Thus, we have copper and carbon with 
the mixture of bichromate of potash and sulphuric acid 
already mentioned. Copper and zinc with SO3 and flowers 
of sulphur. The Bunsen solids with sesquichloride of 
iron, etc. 

The Dry Pile, invented by Zamboni, consists of many 
thousands of alternate disks 
of zinc and silver paper ; or 
of silver paper, with a paste 
of black oxide of manganese 
and gum, spread on the 
wrong side, without the 
zinc; arranged in a glass 
tube or other insulating 
support. (See Fig. 99.) 

CJX- 




102 



GALVANISM. 



Fi^. 100. 




The natural moisture of the paper here serves the office 

of au exciting fluid, and 
very intense, though 
feeble effects are pro- 
duced. Thus, the ex- 
tremities will attract light 
bodies, and even give 
minute sparks ; exhibit- 
ing in fact rather the 
effects of statical, than 
of dynamical electricity. 
This results from the 
great number of ele 
ments, and bad conduct 
ing power of the pile, 
which favors a separation 
of the fluids, but not the 
establishment of a cur- 
rent. One of the piles, 
thoroughly dried, ceases, 
to act ; but recovers on 
exposure to moist air. 
A double column of this 
sort arranged as in (Fig. 
100) will keep the light 
ball, a, vibrating between 
its poles for years. 
Gas Battery.— See page 109. 

Management of Gralvanic Batteries. — Where a number 
of cells are to be used together, they should be united in 
different ways, according to the effects which we desire 
to obtain. If great resistances are to be overcome, as in 
the electric light, the heating of fine wire, etc., they 
should be placed in a series, as indicated by (Fig. 101), 
whoiT a Bunsen battery is shown in ground plan, the 





ii 








1 


11 


1 


1 


1 


111 


1 




GALVANISM. 



103 



carbon of each cell being connected with the zinc of its 

right hand neigh- 
Fig. 101. 



bor. This gives 

us a current of 

intensity, great 

in proportion to 

the number of 

the cells (within certain limits), and of quantity, pro- 

portional to the size of a single cell. 

If the resistance to be overcome is very small, as when the 
current has only to pass 





through a short and good ^^°' ^^^• 

conductor, the cells should 
be united, as shown in 
(Fig. 102), all the zincs 
being joined together at 
one side, and the carbons 
at the other ; then, con- 
necting Z and C, we obtain a current, whose intensity is 
only that of a single cell, but whose quantity is pro- 
portional to the number of cells employed. 

Usually we require in electrical apparatus, some in- 
tensity, with as much quantity as we can get. A good 

Fiff. 104. 








practical arrangement for ordinary apparatus is shown 
(Fig. 103), and for a Ruhmkortf of 9 inch spark, or under, 



104 GALVANISM. 

in Fig. 104. For larger coils the series should be in- 
creased in quantity, but not in intensity, until we come 
to the large coils of 16 to 20 inches, when 15 cells should 
be used, in three rows, giving intensity of three, and 
quantity of five. 

In setting up a nitric acid battery, it is most conveni- 
ent to mix the dilute acid in the cells beforehand, then 
to put in all other parts, and make the connections ; and 
lastly, to pour in the nitric acid. This prevents the 
dulling of the connections by fumes, and saves nitric 
acid ; as the cells get soaked with the diluted sulphuric 
acid beforehand. 

The mixed liquids to be used should always be mixed 
beforehand, and allowed to cool entirely. 

In all large batteries the connections should have as 
much contact surface, and be as large in section, as pos- 
sible. 

After use, the battery should be taken apart, as soon 
as possible. More injury will occur to a battery, while 
standing disconnected, than when it is in active use; as 
the local currents have at this time full play. The zinc 
elements should be well washed, drained, and kept (apart 
from the other portions of the battery) in as dry a place 
as possible. The porous cells and carbons should be 
kept in water, if to be used soon again, and soaked for at 
least a week (in water frequently changed), before being 
dried and put away. To put away porous cells, etc. 
(which have been simply washed after use), in contact 
with the zinc elements, is to insure great injury, and 
perhaps even destruction, to the battery. 

Carbons used with such batteries as that described, 
page 100, should be soaked in diluted nitric acid, when 
they become coated with a white deposit of oxide of zinc, 
or the like. 

Amalgamation. — Zinc is the active element employed 



GALVANISM. 105 

in all batteries, and on account of certain impurities 
which cannot be removed, but by very expensive treat- 
ment, is subject to " local action ;" that is, a little speck 
of some foreign substance will form, with the zinc im- 
mediately around it, a little galvanic pair, which will 
cause a rapid corrosion of the zinc, formation of hydrogen 
bubbles, interference with, and opposition to the general 
current of the battery, and other evils. To remedy this 
difficulty, we resort to amalgamation ; that is, coating the 
surface of the zinc with mercury, which unites with it, 
and practically excludes all such local action as we have 
described, preventing, in fact, to a great degree, any 
chemical action between the liquid and metal, until the 
entire galvanic circuit is closed, and the true chemico- 
electric action begins. 

Batteries in use should be thoroughly amalgamated. 
This is best done some days before they are to be set up, 
as zincs freshly amalgamated, sometimes heat, and suffer 
local action, in an unaccountable manner. 

Effects of the Galvanic Currents. 

Heating and Lnminous. — We have already noticed that 
a wire is heated by a current, which it is unable to 
conduct, and that the discharge of a battery of Ley- 
den jars will thus fuse and vaporize gold, iron, plati- 
num, etc. (page 83). Similar effects are produced by a 
galvanic current. Thus, the current from 40 Bunsen cells, 
8 inches high, will keep 6 feet of platinum wire, No. 2Y, at 
a bright red heat, 3 feet at a white heat, and will fuse a 
sliortcr piece. By cooling part of the wire, as with a wet 
cloth, we make the rest hotter; because more electricity 
can pass by the cool wire, heat diminishing the conducting 
power. The surrounding medium has a certain effect on 
this experiment, for a draft of air will cool the wire ; as 



10(5 



GALVANISM. 



Fig. 105.' 



also will £;uch a gas as hydrogen, on account of the mo- 
bility of its particles. 

Luminous Effects. — When a very powerful series, of 30 
or 40 elements, is terminated by points of dense carbon, 
and these, being first in contact, are separated a little, a 
most dazzling light is produced. In this case particles of 
the carbon are driven across from the positive to the nega- 
tive pole, causing such vibrations as produce intense light 
to take place in both the points, and to some extent in the 
flying particles. This may be admirably shown where the 
points, regulated as they burn away by Duboscq's Electric 
Lamp, are placed in a lantern, and, through a diaphragm, 
throw an enlarged inverted image of themselves on the 
screen. 

If the lower or positive point in the lamp is replaced by 
a cup of carbon, holding a fragment of 
silver, and the discharge is taken from 
this, the light given off is green, the 
length of the discharge is increased 5 
times, and the negative point becomes 
beaded with drops of liquid silver, car- 
ried over by the current. On the 
screen we see the image shown at 
Fig. 105. 

The flame, emerald green, and like 
a tongue licking the point, now on one 
side, now on another: the points red, tipped with white, 
and the silver drops, like so many beads of dew. 

This discharge, called the electric light, when produced 
from a single series of 48 Bunsen elements, is equal to 572 
candles. By increasing the number of elements in series 
above this, the gain in intensity of light is small, though 
the arch of flame may be made longer; thus 46 elements 
give an intensity of 235, and 80 elements of 238. But by 
increasing the quantity, as by using three parallel series 




GALVANISM. 



107 



of 36 elements, the intensity rises to 385 ; that of sunlight 
being 1000. 

We have reason to believe, from certain spectral lines 
and fluorescent effects, that the intensity of heat and light 
in the electric discharge is greater than in the sun. See 
Paper by Wm. A. Miller, in Proceedings of Royal Insti- 
tute, 1863, p. 47. 

Chemical Effects of the Galvanic Current. 
If the poles of a galvanic battery are placed in any com- 
pound fluid they tend to separate it into its constituents, 
the positive being attracted to and collecting around the 




negative pole, and the negative about the positive pole 
Thus, if we have a U tube, with a solution of sulphate of 
soda colored by tincture of cabbage, and plunge two plati- 
num strips, forming the terminals of a battery, in the ends, 
the acid or negative element of the salt will collect about 
the positive pole, turning the cabbage-purple red in that 
limb, while the alkali, or positive constituent, will collect 
about the negative pole, and turn the purple of that limb to 
a rich green. Again, if the fluid contains but two ''ele- 
ments,'*' as water (consisting of oxygen and hydrogen). 



108 



GALVANISM. 



these will likewise be separated and eliminated. Thus the 

glass vessel, Fig. 107, 
containing water, and 
having two platinum 
strips let into it below, 
connected with the 
battery, the oxygen 
will be given off at the 
positive pole, and the 
hydrogen at the nega- 
tive, and these, rising 
in bubbles, may be 
collected in tubes ar- 
ranged for the pur- 
pose. 

This action, called 
Electrolysis, is in- 
deed our most potent 
means of effecting the 
decomposition of 
chemical bodies. So- 
dium, potassium, etc., 
were discovered by 
this means ; by this 
means also we mea- 
sure the quantity of a 
galvanic current, the amount of water decomposed, and of 
gas evolved, being in proportion to the quantity of the 
current passing, we therefore have an apparatus, arranged 
like the preceding, except that both gases are collected 
together and measured, the amount collected in a given 
time, indicating the quantity of the current. Figs. 108 
and 109 show two forms of this apparatus. The first is 
the most complete and efficient, but the second is the 
simplest and most easy of construction. The cork and 
wires must be well coated with sealing wax. 




GALVANISM. 

Fig. 108. 



109 




The great industrial ap- Fig- 109. 

plication of this same action, 
in electro-plating and gild- 
ing and electrotyping, must 
not be forgotten. Here, the 
matrix or mould being made 
of, or covered with a con- 
ducting material, is suspend- 
ed in a solution of the metal 
to be deposited, and made 
the negative pole of a gal- 
vanic series. The positive 
metal is then deposited on 
this in so solid a state as to 
form a complete plating, or 

admit of being itself removed and used for printing, etc., 
as the case may be. 

Gas Battery and Secondary Piles. 

After the apparatus. Fig. 107, has been used for a few mo- 
ments, if it is disconnected from the battery and connected 
W'ith a delicate galvanometer, a current will be shovni, op- 
10 




110 



GALVANISM. 



posito to that of the original battery. This is produced 
by films of oxygen and hydrogen attached to the platinum 
plates. On this principle Grove constructed his gas bat- 
tery. So also powerful "secondary piles" may be pro- 
duced by immersing two or more plates of lead in a solu- 
tion of Glauber salt, connecting the end plates with a bat- 
tery, and after a time disconnecting. 

Properties of Currents Moving Freely in Wires. 

Magnetizing Effects. — We have already noticed that a 
current passing around a bar of iron renders it a magnet, 
permanently if the bar is of steel, temporarily if the bar 
is of soft iron (page 92). This action is well shown in 
many pieces of apparatus, such as the divided ring, the 
armature engine, &c. 

Fig. 110. 




The most remarkable application of this action is, how 
ever, found in the first telegraph practically applied, i. e. 
that of Morse (Fig. 110). In this an intermittent current 
(whose breaks and flows are controlled by an operator at 



GALVANISM. 



Ill 



one end of a long circuit), causes, at the other end, an ar- 
mature or bar of soft iron, attached to a lever, to be re- 
peatedly attracted by an electro-magnet set beneath it, and 
thus makes a pencil at the other end of this lever produce 
upon a moving band of paper, dots by a short and strokes 
by a more continued pressure. An alphabet of these marks 
being pre-arranged between two operators, communication 
may be thus made through great distances with indefinite 
velocity. 

By ingenious and elaborate arrangements of mechanism, 
the message sent is automatically printed by the apparatus, 
as in the instrument of House or of Hughes, and is even 
in that of Bain reproduced in an autographic copy. 

Velocity of Galvanic Currents in Good Conductors. 

This, according to experiments of the U. S. Coast Sur- 
vey, is about 18.100 miles per second in land lines, but 
through submerged cables the velocity is much less. 

Magnetic Properties of Coils or Solenoids. 

As might be antici- Fig. ill. 

pated from the theory of 
magnets, a coil or solen- 
oid (Fig. Ill) through 
which a current is pass- 
ing, has all the proper- 
ties of a magnet. It 
will attract iron, repel 
with its poles the like 
and attract the unlike 
poles of magnets, ar- 
range itself north and 
south, and, in fact, comport itself in all respects like a 
magnetic bar. 




112 



GALVANISM. 



Pig. 112. 




Again, Slich a Coil will tend to draw into 
itself a bar of iron whose end is brought within 
its reach. This is well illustrated by the ex- 
periment of the suspended bar (Fig. 112), and 
by Page's coil engine, in which bars attached 
to cranks and alternately drawn into coils, are 
caused to operate machinery. 

Again, snch a Coil will cause a magnetic 
needle to stand at right angles to the planes of 
its circular currents. This principle is applied 
Fi^. 113. 




GALVANISM. 113 

in the apparatus used for measuring the intensity of cur- 
rents ; for the amount of deflection will vary in a known 
ratio to the intensity of the current. For currents of 
small quantity the Galvanometer (Fig. 113) is used. 
This consists of a heavy flattened coil of wire, within and 
over which an astatic pair of needles is suspended. The 
deviation of these is noted on a circular graduated scale, 
when a current is passed through the coil by means of the 
binding screws. 

For currents of great quantity we employ the Tangent 
Compass (Fig. 114), which consists of a band of copper, 
bent nearly into a ring, supported on a stand, with a 
binding screw attached to each end, and with a small 
compass-needle supported at the centre. With this in- 
strument the intensity of the current is proportional to the 
tangent of deflection of the needle. 

A Solenoid will be acted upon by a current in this, as in 
other respects, exactly like a magnetic needle. By reason 
of this " tangential force," also, a wire carrying a current 
tends to revolve about a magnet parallel, or nearly par- 
allel to it. 

Again, a Magnet will likewise rotate around a current — 
as may be proved in a similar mannerrr— and also around 
a current, passed through half its own length. 

Many effects similar to the foregoing may be developed 
by the magnetic action of the earth, and may be readily 
explained, on the principles already stated, by regarding 
the earth as a great magnet, with its north pole (in a 
magnetic sense) at the south, and the south pole at the 
north extremity of its axis. 

Wires carrying currents in the same direction attract 
each other. 

Wires carrying opposite currents repel each other. 

A conductor carrying a current between the poles of a 
10* 



114 



GALVANISM. 

Fig. 114 




U magnet, at right angles to the line joining them, is re- 
pelled. 

Galvanic Induction. By Currents and Magnets. — If two 
wires are placed parallel to each other, and an intermit- 
tent current is passed through one of them, at every in- 
terruption of the flow an instantaneous "induced or 



GALVANTSa^. 



115 



SECONDARY CURRENT," coincident in direction with the 
first or " PRIMARY CURRENT," will be developed in the 
other wire. At every renewal of the primary, on the 
other hand, a momentary induced current will be devel- 
oped in the other or "secondary wire," opposite in direc- 
tion to the "primary." 

These induced currents may be best shown by using 
coils or helixes of wire, wound on spools or bobbins. 
Thus we have a large bobbin of fine wire, A, for the 



Fig. 115. 



t 




secondjary, and a smaller one, B, of thick wire, fitting into 
the fomier, for the primary current. 

These beinc: put in place, and an intermittent current 
passed through B, the secondary, developed in A, may 
be demonstrated by connecting its ends with a galvanom- 



116 



GALVANISM. 



eter, or by holding them in the hands, when a shock or 
series of shocks will be perceived. 

A like effect would be produced if, in place of interrupt- 
ing the current in B, we left it continuous, and then rap- 
idly moved B out of and into A. 

A magnet may be similarly used, as a substitute for B, 
being thrust into, and withdrawn from A, with the same 

Fig. 116. 




iiftct ; or we may place a bar of soft iron in A, and then 
ause it to receive and lose magnetism by the approach 
nd withdrawal of a permanent magnet. This will of 
oour^ie be precisely equivalent to inserting and withdrawing 
it. This is the principle of action in the magneto-electric 
machine, Fig. 116, and others of like nature. By such 
means, many magnets being employed, currents are oo- 



GALVANISM, 



in 



Fi-. 117, 



tained capable of electro-plating on the large scale, of illu- 
minating light-houses with the electric light, etc. 

Lastly, we may put B in its place, insert a soft iron bar 
in the centre of it, and then pass a discontinuous current 
through B ; we shall then have the combined inductive 
effect of the coil and magnet. This is realized in the or- 
dinary medical induction coil 
(Fig. IIT). A bar of iron 
may have excited on its 
surface an induced current, 
which interferes with its in- 
fluence on the secondary 
coil. For this reason a bundle of needles is more effective 
than a bar. If these needles are surrounded by a con- 
ducting envelope, such as a tube, their efficiency is again 
reduced, unless this tube has a longitudinal opening to 
interrupt its conducting power. 

A secondary helix, like that just described, if made of 
very great size, constitutes the apparatus known as the 
Ruhmkorff coil, which yields a secondary current of so 
great intensity as to possess all the properties of statical 




Fix. 118. 



JL 






m 



118 GALVANISM. 

electricity. This coil, as originally constructed by Ruhm- 

korff, is shown (Fig. 118) as improved by E. S. Ritchie, Esq., 

of Boston, in Pig. 119. (See Franklin Institute Journal, 

vol. 40, p. 64.) 

Fig. 119. 




To both these coils, when a great resistance is to be 
overcome, as when the spark is to be passed in air, the 
"condenser-'' of Fizeau is an addition of great importance. 
This consists of two sheets of tinfoil of great extent, 40 to 
100 square feet, separated by oil or gummed silk, folded 
away in compact form (in general, packed in the base on 
which the rest of the apparatus is supported), and con- 
nected with the primary circuit, at each side of the point 
where it is interrupted. This condenser delays the action 
of the extra-current (to be presently described), and so 
enables the electricity to collect and overcome a resist- 
ance before this interfering action can take efifect. Where 
the resistance is small, as in discharges in a vacuum, or 
through good conductors, the condenser is not required. 
The largest coils of this sort contain 30 miles of wire Jn 
the outer helix, and give sparks of 20 inches in length 



GALVANISM. 



119 



This coil is at once the most convenient and powerful 
means of producing statical electricity within our reach. 
With 6 to 10 Bunsen cells, one of Ritchie's 6 to 15 inch 
coils will produce a continuous stream of sparks 6 to 15 
inches in length ; will charge a large Leyden jar, so that it 
will be discharged with a report like a torpedo many times 
in a second; and will operate all electrical vacuum experi- 
ments with a splendor and volume of light entirely unap- 
proached by any other electrical apparatus. It is not, 
however, fit to perform experiments of attraction and re- 
pulsion, because the fluids are developed in it, not steadily, 
but in a series of instantaneous flashes. 

The Extra-Currents. — This is the name given to induced 
currents, similar to those above described, which are 
developed in a primary wire at the moment of making 
and breaking connection. The inverse extra-current, de- 
veloped at making connection, is of course overcome by 
the opposing primary then started ; but the " direct " extra- 
current produced at breaking circuit, shows itself very 
fully. It occasions the bright spark seen at breaking con- 
nection, where the circuit passes by a long wire, espe- 
cially if this is coiled, and may be made to give a shock, 
fuse platinum wire, etc., exactly as the ordinary induced 
current would. 

It is often used in medical batteries, and is then gener- 
ally called "the primary induced or Henry current." 

Currents are also induced by magnets in moving con- 
ductors. Thus, a 

copper disk being '^^ 

rotated under a 
compass needle, 
will have currents 
developed in it, 
which, by their ac- 
tion on the needle, will cause it to revolve about its point 
of support. 




120 GALVANISM. 

Again, a disk of copper rotated between the poles of a 
powerful magnet becomes very hot by reason of the cur- 
rents developed in it ; in fact, Tyndall using a brass tube 
in this way has melted fusible metal in it in 1^ minutes. 

Thermo-Electricity. 
If tw^o different metals, such as Bismuth and Antimony, 
united at one point, be heated at this junction, a current 
of electricity will be established between them in one 
direction; if they are cooled in the same place the current 
will be reversed. If, therefore, many such 
'^' ^-^^ bars be joined alternately, as in Fig. 120, 
W)]^'B heated at one side, A B, and cooled at the 
other, C D, a sort of battery will be pro- 
duced, and a strong current obtained. The 
flow thus developed is called Thermo Elec- 
tricity, but is in all respects identical with 
the galvanic current of the battery. In the following 
table many substances are arranged in order, from, the 
most positive Bismuth to the most negative Tellurium. 
Any one of these will be positive to any below, and nega- 
tive to any above it; that is, when heated with one below 
the positive fluid w^ould pass to that other metal by the 
junction, and so on. Here, as in the battery, how^ever, 
the positive pole will be connected with the negative ter- 
minal element 




Bismuth, 

Nickel, 

Cobalt, 

German Silver, 

Brass, 

Lead, 

Tin, 



Copper, 

Platinum, 

Silver, 

Zinc, 

Iron, 

Antimony, 

Tellurium. 



According to Bunsen and Becquerel (see Jour, of Fr. 



GALVANISM. 



J21 



fnst., Yol. 49, p. 422), the most powerful series of any may 
be made of copper, pyrites, or sulphide of copper, and me- 
tallic copper. 

This development of electricity by heat 
may be well shown by the thermo-elec- 
tric revolving arch, Fig. 122, where the 
lamp, heating the junction of the brass 
ring with the iron arch, causes a current 
which rotates the frame, so as to bring 
the other junction into the lamp, when 
the same thing is repeated, and a rota- 
tory movement is thus kept up. 

This action, by which heat develops a 
galvanic current, is of great use in the 
measurement of very delicate variations 
of temperature; for by connecting a small thermo-electric 
combination or pile, as Fig. 123, with 
a delicate galvanometer, changes of 
temperature may be noted which would 
otherwise escape all observation. Such 
an arrangement is called a Thermo- 
MULTiPLiER, and is of inestimable value 
in most branches of physical research. 





Animal Electricity. 

Some fish, such as the Raia torpedo, and the gymnotus 
or electrical eel, by reason of a peculiar anatomical struc- 
ture within their bodies, in some sort resembling a gal- 
vanic pile, develop notable quantities of electricity, so that 
they give a very severe shock if touched, and may be 
caused to magnetize a bar of iron, fuse gold-leaf, etc. 
Though this intense and special manifestation of electric 
11 



122 GALVANISM. 

disturbance is confined to a few creatures, provided with 
a peculiar set of organs, electrical action goes on in some 
degree in all living animals, and is closely connected with 
their vital actions. Thus electric currents can be proved 
to exist in the muscles when these are in action, and a sort 
of galvanic battery can even be produced by connecting in 
order, many portions of muscular substance. 

The subject of animal electricity, in its relation to phy- 
siology, is one of great interest ; but it is as yet too much 
mixed with doubtful theory, and too extended in its scope 
for discussion in this place. 



Spectra 



A BT P Rb K 



G 






K 
Bb 





PS Du.vd.l i^- SonLith .Phila.d^ 



PART II. 



CHEMISTRY. 

General Definitions. 

Clieinistry is that science which treats of the distin- 
guishing properties of bodies and of their actions under 
the influence of Chemical Affinity. 

Distinguishing Properties are those possessed by certain 
substances exclusively, and by which they may, therefore, 
be recognized. Ex. Gold has a specific gravity of 19.26, 
a yellow color, and melts at 2016° F. ; these properties 
make it distinguishable from other substances. 

Chemical Affinity is that force of attraction which exists 
between the particles of substances of a different nature, 
causing them to unite so as to form compounds, having 
properties unlike those of the constituents. 

1st. It acts between particles, i. e. only at insensible 
distances, thus requiring an intimate mixture or approach 
«f particles to bring them within its range. Thus sulpluir 
and chlorate of potash mingled in lumps effect no combi- 
nation, but if ground together in a mortar a violent com- 
bination takes place (a few grains onl}^ should be used 
for this experiment). From this fact arises tlie utility oi' 
pulverization, fusion, and solution in conducting chemical 
actions. 

(123) 



124 CHEMISTRY. 

2nd. It acts between substances of a different nature. 
Thus acids will combine with alkalies, and vice versa, but 
not acid with acid, or alkali with alkali. As a general 
rule, the more different the properties of the substances, 
especially in an electrical sense, the greater their force of 
combination. 

3rd. It causes the iormatiou of compounds with prop- 
erties different from those of their constituents. These 
differences are chiefly in (a) Color, (5) State, (i. e. solid 
liquid or gaseous), (c) or in Temperature. 

(ft) To illustrate changes in color. Prepare seven glasses 
containing solutions in water of the following substances : 
I. Ferrocyanide of potassium. II. Chromate of potas- 
sium. III. A mixture of the foregoing. lY. Sulpho- 
cyanide of potassium. V. Hydrosulphate of Ammonium. 
YI. Sulphuric Acid. YII. Ammonia. To each of these 
add a solution of nitrate of lead containing a little sesqui- 
nitrate of iron. The colors then, originally light yellow 
or white, will become as follows : I. Blue, II. Yellow, III. 
Green, lY. Red, Y. Black, YI. Milk-white, YII. Buff. 
Two blacks make a white. Make some ink in a glass by 
mixing in it tincture of galls and per-sulphate of iron. 
Drop into it some crystals of chlorate of potash. Make 
some common sulphuric acid black, by stirring it with a 
stick. Pour the black acid into the ink, and a clear solu- 
tion like water will result. 

(6) Changes in state. Two solids rnuke a liquid. Grind 
together in a mortar crystals of NaOjSOg* (6 parts) and 
NH^ 0,]Sr05 (5 parts). They will form a liquid. Mingle a 
saturated solution of CaCl. with a little oil of vitriol dilu- 
ted with half its bulk of water. These clear liquids will 
form an opaque solid. Two gases make a solid. Rinse 
one glass with a few drops of Ammonia and another with 

* NaO,S03 = Glauber salt, NH40,N05= Nitrate of Ammonia. CaCl =» 
Chloride of Calcium. 



INORGANIC CHEMISTRY. 125 

Muriatic acid. Place their openings together; they will 
be filled with solid particles forming a dense cloud. 

(c) Differences in temperature. Pour oil of vitriol into 
water, introduce a test tube containing water, and stir it 
about. The water in this will boil. Pour water on an- 
hydrous CuOjSOs* or on Lime (CaO.); both will become 
intensely hot and give off steam. The laws which govern 
this force will be found on page 295. 

Substances are of two kinds: 

Inorganic or mineral, as metals, gases, rocks, &c., and 

Organic, or those connected with "life," as wood, flesh, &c. 

Organic bodies differ from inorganic in so many ways 
that they are best considered separately under the head 
of Organic Chemistry. Moreover this branch of the sub- 
ject can be developed more clearly after we have explained 
the laws which regulate the formation of the much sim- 
pler substances, in the domain of Inorganic Chemistry. 

INORGANIC CHEMISTRY. 

Inorganic bodies are either Elements, Binaries, Terna- 
ries or Quarternaries. 

1st Elements are those bodies which have never been de- 
composed or separated into others. Their number is about 
G5, of which 52 are metals and 13 metalloids or non- 
metallic elements. The following table contains a list of 
these elements, with their symbols and atomic weights, 
combining proportions or equivalents. The names in brack- 
ets are those from which the symbols of certain bodies 
have been derived : 6 of these are metals known to the 
ancients and still retaining in this sense their Latin names, 
Sb Au Fe Pb Hg Sn. Two discovered in modern times 
follow their example, and one takes its name from a Ger- 
man mineral in which it was first found. 

* CuO,S08= Sulphate of Copper. 
11* 



126 



INORGANIC CHEMISTRY. 



Table of the Elements. 



Names of Elements. 



Aluminum 

Antimony (Stibium).. 

Arsenic 

Barium 

Bismuth 

Boron 

Bromine 

Cadmium 

Caesium 

Calcium 

Carbon 

Cerium 

Chlorine 

Chromium 

Cobalt 

Copper 

Didymium 

Erbium 

Fluorine 

Glncinum .... 

Cold (Aurum) 

Hydrogen 

Iodine , 

Indium 

Iridium 

Iron (Ferrura) 

Lanthanum 

Lead (Plumbum) 

Lithium , 

Magnesium 

Manganese 

Mercury (Hydrargyrui 
Molybdenum... 



o 
1 

Al 


1 

13.7 


Sb 


120.3 , 


As 


75 i 


Ba 


68.5 


Bi 


208 , 


B 


10,9 


Br 


80. 


Cd 


56 ! 


Cs 


133 1 


Ca 


20 I 


C 


6 


Ce 


46 


CI 


35.5 1 


Cr 


26.7 


Co 


29.5 


Cu 


31.7 


D 


48 


Er 




F 


19 


Gl 


26.5 


Au 


197 


H 


1 


I 


127 


In 


37.07 


Ir 


99 


Fe 


28 


Ln 


47 


Pb 


108.7 


Li 


7 


Mg 
Mn 


12 

27.6: 


Hg 
Mo 


100 

47.88 i 



Names of Elements. 



Nickel 

Niobium 

Nitrogen 

Osmium 

Oxygen 

Palladium 

Phosphorus 

Platinum 

Potassium (Kalium). 

Rhodixim 

Rubidium 

Ruthenium 

Selenium 

Silicon 

Silver (Argentum).... 
Sodium (Natronium) 

Strontium 

Sulphur 

Tnntalum 

Columbium 

'I'ellurium 

Terbium 

Thallium 

Thorium 

Tin (Stannum) 

Titanium 

Tungsten (Wolfram). 

Uranium 

Vanadium 

Yttrium 

Zinc 

Zirconium 



Nomeiiclatiire of Elements. — Many elements bear in 
chemistry the same names as in common language. Ex. 
Zinc, Sulphur, Iron. Others are named from some striking 
peculiarity. Ex. Bromine derives its name from a Greek 
word meaning stench, in consequence of the disgusting 
odor it evolves Others from the place or substance in 
which they were discovered, Ex. Columbium, because 



INORGANIC CHEMISTRY. 127 

it was found in an American mineral. Tantalum aerives 
its name from tantalite, the mineral wherein it was first 
found. All the newly-discovered metals are made to ter- 
minate in um or ium. Ex. Platinum, Caesium, Ruthe- 
nium. 

Symliols of Elements. — A symbol is a letter or combina- 
tion of two letters used to indicate one equivalent of the 
element for which it stands. We have therefore a symbol 
for each element, as O for Oxygen, H for Hydrogen, etc. 
The symbol is either the first letter or the first and char- 
acteristic following letter in the name of the element, 
as will be seen by reference to the above table. This 
second letter is added for distinction in those cases where 
the names of the two elements commence with the same 
letter. Thus, Carbon and Chlorine both commence with 
the letter C. In order to distinguish these two bodies, we 
must add the characteristic letter I in the name of the 
body last discovered, Chlorine, to its first letter C, so as 
to have a separate symbol, CI, for Chlorine. It will be 
noticed that the second letter is added in smaller char- 
acter; and, moreover, the definition of symbol, given 
above, makes it stand for only one equivalent of the ele- 
ment. 0, for example, does not represent the substance 
Oxygen in general, but merely 8 parts by weight of Oxy- 
gen. F should not call to mind Fluorine, but 19 parts 
relatively by weight of Fluorine. Since a symbol stands 
for one equivalent of the element, we must place figures 
if we wish to indicate several equivalents : thus the 
symbol Au stands for 1 equivalent of gold. To represent 
5 equivalents of gold we write 5Au. In writing the for. 
mulae of compound bodies, however, the figure is placed 
after and a little below the symbol: thus the compound 
of Nitrogen, N, with 5 equivalents of Oxygen, 50, is not 
represented by N50, but by NO5, 

2nd Binaries. — Binaries are compounds of two ele- 



128 INORGANIC CHEMISTRY. 

ments, They are divided into three orders: I. Acids; 
II. Bases; and, III. Neutrals. 

An Acid is a body having a sour taste, reddening a so- 
lution of litmus, or of violets or red cabbage, and turning 
a solution of cochineal yellow, and combining with bases 
so as more or less to destroy their basic properties and to 
form with them salts. 

A Base is a body having a peculiar soapy taste, redden- 
ing a solution of turmeric, turning one of violets or cab- 
bage green, and one of cochineal purple ; and combining 
with acids to form salts, with mutual neutralization of 
properties. 

In both these definitions the last point only is universal 
in its application. Alkalies are strong bases which fulfil 
all the conditions above expressed. 

A Neutral Body is one so devoid of all active properties 
that it can scarcely be made to enter into combination. It 
occupies an intermediate position between acids and bases. 

I. Acids are again of three sorts, (a) Those contain- 
ing Oxygen or Sulphur in union with a metalloid or 
metal, as — 

Arseiiious acid = AsOg I Carbonic acid = COj 

Sulpharsenious acid =: AsSg | Sulphocarbonic acid = CSj 

(b) Those containing Sulphur, Selenium, or Tellurium, in 
union with Hydrogen, (c) Those containing Chlorine, 
Bromine, Iodine, Fluorine, or Cyanogen, in union with 
Hydrogen. 

(a) Acids of the first class, which contain Sulphur, are 
distinguished from those containing Oxygen, by prefixing 
sulph or sulpJio to the name of the corresponding oxygen 
acid ; thus AsSa corresponds to AsOg, Arsenic Acid, and 
accordingly we give to the first the name Sulpharsenic 
Acid. 

The name of the oxygen acids themselves are derived 
from the names of the metalloids or metals with which 



INORGANIC CHEMISTRY. 129 

the Oxygen is combined. Ex. The acid body formed by 
the union of Chlorine with Oxygen tal^es its name from 
the metalloid, and is called Chloric Acid. 

When there are several compounds of Oxygen with the 
same element, the one which contains the most Oxygen 
is made to terminate in ic ; the one containing the least in 
ous. If another acid is afterwards discovered, containing 
more Oxygen than the acid which was made to terminate 
in ic, hyper (abbreviated per) is prefixed to the new acid, 
to distinguish it from the acid first discovered. Hypo 
denotes less Oxygen than the remainder of the name im- 
plies. The above rules are exemplified in the following 
series of acids : — 



Perchloric acid 


= 


CIO7 


Chlorous acid 


= 


CIO3 


Hypochloric acid 


= 


CIO4 


Hypochlorous acid 


= 


CIO 


Chloric acid 


= 


CIO5 









(b and c) The names of acids of the second and third 
class are formed by prefixing hydro to the name of the 
electro-negative element. 



(b) Hydrosulphuric acid =r HS 
Hydroselenic acid = HSe 
Hydrotelluric acid =:= HTe 



(c) Hydrochloric acid = HCl 
Hydrofluoric acid =:r HF 
Hydrocyanic acid = HCy 



And it will be noticed that the symbol likewise of the 
electro-negative element is written last in the above ex- 
amples. 

II. Bases are named from both elements which compose 
them, the more electro-negative being named first. Ex. 
Oxygen being negative to iron, these when united form 
Oxide of Iron. 

In writing the formulae of bases, however, the symbol 
of the electro-negative is placed last. Thus we express 
this same substance, Oxide of Iron, by FeO. 

If the compound contain one equivalent of the electro- 
negative element to each equivalent of the electro-positive 



130 INORGANIC CHEMISTRY. 

one, prot or proto is prefixed to the name of the negative 
element; if 2 equivalents of the negative to each of the 
positive, deut, deiito, hi, or hin is prefixed ; if 3 negative to 
2 positive, sesqui ; if 3 negative to each positive, trit, 
trito, or ter ; if 4 negative to each positive, quad or 
quadro ; if 5 negative to each positive, pent or penti. Ex. 
FeO, 1:1; Protoxide of Iron, FeOg, 1:2; Binoxide of 
Iron, Fe^Oa, 2:3; Sesquioxide of Iron, FeOs, 1:3; Ter- 
oxide of Iron. 

III. Neutral Bodies are of two kinds. 1st. Those formed 
by the union of a halogen* body with a metal ; they are 
marked by peculiar characteristics, and are known as 
Haloid Salts. 2nd. All other compounds of two elements 
which are neither acids nor bases. Both classes are named 
exactly like bases. Ex. NaCl, Chloride of Sodium. MnOj, 
Binoxide of Manganese. 

3rd. Ternaries. — Consist of an acid and a base. The 
negative element, in both acid and base, must be the same. 
Ex. Arsenate of Potassa, K0,As05. Sulpharsenate of 
sulphide of potassium, KSjAsSg. Every such union of 
an acid with a base is called a Salt. If an oxygen acid is 
united with an oxygen base, we have an Oxygen Salt ; if 
a sulphur acid with a sulphur base, a Sulphur Salt. An 
oxygen salt is named by giving the name of the acid first, 
with its termination changed from ic to ate, and from ous 
to ite, and then adding the name of the positive element 
in the base, "oxide of" being understood. Ex. Sulphate 
of Iron, FeOjSOg. A sulphur salt is named in the same 
way, but "sulphide of" is expressed. If the acid be to 
the base in the ratio of 1 : 1, proto is prefixed to the name 
of the salt ; if as 2:1, bi ; if as 3 : 2, sesqui, etc. Salts 
are divided into three classes : 1st. Acid Salts. 2nd. Neutral 
Salts. 3rd. Basic Salts. See page 179. 

* Halogen, from a\6s, salt; yevvdo), I produce. They are Chlorine, Bro- 
mine, Iodine, Fluorine, and Cyanogen. 



OXYGEN. 131 

Sym. 0. OXYGEN. Eq. 8. 

Oxygen was discovered, independently of each other, by 
Priestley and Scheele, in 1174. It was called by Priestley 
" dephlogisticated air," and by Scheele " Empyrean air." 
Its true nature was pointed out soon after by Lavoisier, 
to whom it owes its present name of oxygen, 6^vs acid, 
yevvdio, I produce. Because it was supposed to form all 
acid compounds. This idea is in a general way correct, 
but by no means universally true. Most acids contain 
0, but many do not. 

Sources of 0. — Oxygen constitutes 46 per cent, by 
weight of all the principal rocks, granite, basalt, gneiss, 
sandstone, and limestone ; 30 per cent, of all the common 
metallic ores; one-fifth of the atmosphere, and eight- 
ninths of all water. 

Preparation of 0. — 1st. By heating Red Oxide of 
Mercury to 750° Fahr., HgO = Hg + 0. This process 
may best be exhibited by placing a little HgO in a test 
tube, supporting this in the retort holder, as in Fig. 124, 
and heating the oxide by means of a Bunsen burner, or 
powerful Argaud lamp, such as in Fig. 125. The decom- 
position soon begins. Metallic Mercury is deposited in 
the cooler portion of the tube, and the escaping gas will 
relight an extinguished match, with a coal yet on it, if 
plunged in the mouth of the tube. 

2nd. By heating to redness Black Oxide of Manganese, 
3Mn02 = MnO + Mn.Og -f 20. This requires an iron 
vessel and the heat of a good fire. 

3rd. By heating Chlorate of Potash which gives off 
39 per cent, of 0, KO^ClOj = KCl + GO. Half an 
ounce of K0,C105 yields 270 cubic inches, or nearly a 
gallon of 0. A pound yields about 30 gallons. 

4th. When a little Black Oxide of iSlanganose is mixed 
with Chlorate of Potash, the Oxygen is disengaged at a 



132 




much lower temperature than otherwise. The Oxide of 
Manganese undergoes no change and seems to act solely 
by its presence. 

The operation may be well conducted on the small 
scale in a glass flask heated by a spirit lamp with an 
"Argand" or large hollow cylindrical wick, as is repre- 
sented in Fig. 125, the gas being collected as it forms, in a 
bell jar filled with water, and inverted over a pneumatic 
cistern. An India-rubber tube serves best to convey the 
gas from the flask to the cistern. In making large quan- 
tities of oxygen it is best to use a copper flask of one quart 
or more capacity, heated by a Bunsen burner which should 
be removed as soon as the gas begins to come over freely; 
the operation will then continue to the end without further 
heating. The gas may then be collected in a gas bag 
made of strong India-rubber cloth, after passing through 




lo 



a large washing bottle, or in such a receiver as is shown 
in Fig. 126, or Fig. 141. 

Fig. 126. 




To use the gas receiver, Fig. 126, we fill A with water 
ny pouring it into B, opening the stopcock a to admit it to 
12 



134 OXYGEN. 

A, and the cock e to allow the air to escape. Then both 
these cocks being closed, we remove the cork from d, and 
pass in, through this passage, the tube carrying the gas 
from the flask. As the gas enters it displaces the water, 
which then runs out around the entering tube at (i, cc are 
merely iron rods supporting B. If after A is full of gas d 
is closed, B filled with water, a bell-jar full of water placed 
in B, and the cocks a and h opened, water will flow through 
a into A and drive out gas through h into the bell jar. 

5th. By strongly heating Red Lead, 2PbO,Pb02, or 
almost any deutoxide of a metal, the oxide will be reduced 
to a protoxide, yielding oxygen. 

6th. By heating Nitrate of Potash (Nitre), K0,N05 = 
KO,N03+20. 

Tth. By heating a mixture of 2 parts strong Sulphuric 
acid (oil of vitriol), and 1 part black Oxide of Manganese, 
Mn02-fS03=MnO,S03+0. 

8th. By heating 4 parts of Sulphuric acid with 3 parts 
of Bichromate of Potash, KO,2Cr03 + 4S03= KO,S03 4- 
Cr2033S03 -f- 30. One ounce of salt yields 200 cubic 
inches of 0. 

9th. By heating Hydrated Protoxide of Barium in alter- 
nate currents of air and steam, when it will take from 
the air and yield it to the steam. 

10th. By heating Nitrate of Soda and Protoxide of Zinc. 

11th. By adding to Hypochlorite of Lime in solution 
(obtained by mixing commercial bleaching salt or chloride 
of lime with water, and decanting or filtering thnmgh a 
cloth) a few drops of nitrate of cobalt, and gently heating. 
In this case the oxide of cobalt which is formed, abstracts 
oxygen from the hypochlorous acid and lime (^leaving at 
last but chloride of calcium), and then in turn abandons 
this oxygen only to seize upon a fresh quantity. 

A pound of Chloride of Lime (commercial) treated with 
about a quart of water will yield in this way 2j gallons 



OXYGEN. 13a 

of oxygen. This process is a curious one, perfectly safe 
and easy to manage, but cumbrous where large quantities 
of gas are required, and no cheaper than the 4th. (See 
Journal of Franklin Institute, Yol. 50, p. 285.) 

12th. By heating together Silica fsand) and Sulphate of 
Lime (plaster of Paris), Si03+CaO,S03=CaO,Si03 + S02 
+ 0. Silicate of lime is formed, and Oxygen with Sul- 
phurous acid passes off. The SO^ is removed by lique- 
faction or absorption in milk of lime, and the thus 
obtained pure. 

Of all these methods the 4th is at present the most 
available. 

Properties. — Oxygen is a gas, incapable of liquefaction 
by cold or pressure, and without color, taste, or smell. Its 
density is l.l05t; 100 cubic inches at 60°, and 29.988 
inches barometric pressure, weigh 34.29 grains. It is 
slightly soluble in water, the latter dissolving at the ordi- 
nary temperature ^J^ of its volume of gas. It is the most 
magnetic of gases (see p. 92) ; in this respect the of 
the atmosphere is equivalent to a shell of iron enveloping 
the earth, and ^\q of an inch thick ; and by its changes 
of magnetism, due to those of temperature, produces the 
diurnal variations of the magnet. It is the great supporter 
of combustion. Almost every case of combustion consists 
in a union of the elements of the burning body with Oxy- 
gen. When bodies burn in the air the great excess of 
nitrogen present carries away much of the heat generated, 
but when oxygen alone is collected in a receiver, the heat 
developed by combustion can rise much higher, and the 
more ready supply of the "supporting body " will greatly 
intensify the action. 

This is well exhibited, as follows : 
We fill bell-jars, such as Fig. 127, with this gas over 
the pneumatic tank, by filling them first with water, and 
then allowing the gas to flow into them from a tube intro- 



135 



OZONE. 




duced under their immersed lower edge. (See Fig. 125.) 
We then attach to wires, or place in copper spoons, as 
their nature requires, pieces of charcoal, candle, sulphur, 
phosphorus, etc. (dry sand should be placed in the spoon, 
under the phosphorus), and ignit- 
ing, plunge them into the jars 
through their upper openings. 
These, bodies then burn with 
great splendor. 

To burn iron, or rather steel, 
we use an uncoiled watch-spring, 
which can be best ignited by the 
oxjhydrogen blowpipe, and then 
plunged in a jar of oxygen, or we 
may fuse a little sulphur fast to its end, light this, and 
then plunge it into the gas. 

Figure 121 represents phosphorus burning in oxygen; 
and Fig. 128 steel, in like case. Ere- 
macausis is the name applied to a very 
slow combination of bodies with oxy- 
gen, by which no light is evolved. 
This we see in decaying wood, and 
vegetable matter generally, in the res- 
piratory process of animals, etc. Oxy- 
gen drawn into the lungs is absorbed 
in the blood, and there combines with 
various dead matter, exhausted tissue, 
and the like, so producing heat needed for the support of 
animal life. 

Ozone and Ant-Ozone. — Besides its usual state. Oxygen 
has two other and dissimilar conditions designated by 
the above names. 

When dry air or oxygen is passed through a glass tube 
containing a number of fine wires coated with glass, 
which form the poles of a Ruhmkorflf Coil, the character 



Fig. 128. 




OZONE. 13t 

of the gas is changed. If it is passed through a strong 
solution of Iodide of Potassium (KI), part of it will be 
absorbed, setting free the Iodine. This is the Ozone. 
Another part will pass on unabsorbed, and may be col- 
lected with the gas which may have escaped action in a 
dry vessel. 

Its chief peculiarity is that in the presence of moisture 
or water, it forms with it a dense white cloud or fume, 
which subsides after half an hour or so, leaving the water 
and common oxygen. This substance so acting is called 
Ant-ozone. These were discovered by Schbnbein, and 
have been thoroughly studied by Meissner. (See Silliman's 
Journal, Yol. 3t, p. 325, 1864, for a review of Meissner's 
book.) 

Ozone is prepared, not only by the action of electricity 
on air, but also in the electric decomposition of water 
(page 108) ; by the action of phosphorus, partly covered 
with water, on air ; by the action of ether, turpentine, 
etc., on air ; by action of oil of vitriol on chameleon 
mineral (Silliman's Journal, 1863, Yol. 35, p. HI); and 
by plunging a red-hot glass rod into a glass having a few 
drops of ether in it. 

Its test is paper moistened with starch, containing a 
little KI (starch, 5 parts ; Iodide of Potassium, 1 part; 
to be boiled), which it turns purplish blue, or the juice of 
mushroom. Boletus luridus. Boletus cyanescenus, etc., or 
the alcoholic solution of the resin of Guaiacum, to which 
it communicates a blue color. 

The properties of ozone are like those of oxygen, but in 
all respects more intense. It has a peculiar smell, sug- 
gestive of scratched varnish, which may be easily per- 
ceived in the vicinity of a powerful Ruhmkorlf coil or elec- 
trical machine. It interferes with vegetation, formation 
of mould, etc. 

Antozone may be prepared, not only in the way above 
12* 



138 



HYDROGEN. 



described, but by action of dilute Sulphuric acid (SO3) on 
Deutoxide of Barium (BaOa) diffused in water at a low 
temperature, and by passing Carbonic acid (COa") through 
BaOa diffused in water. In this case, however, the Anto- 
zone at once unites with water forming HOg. Antozone 
again seems to exist in Fluor Spar of Welsendorf, HO2, 
being formed by grinding this mineral with water. 

Test. — Antozone will develop the blue purple in starch 
containing KI, if very dilute solution of Sulphate of Iron 
(FeQSOa) be first added to that mixture. 

Ozone is often indicated by the symbol + 0, and Ant- 
ozone by — 0, and these are sometimes called positive 
and negative oxygen. 



Sym. H. HYDROGEN. Eq. 1. 

Hydrogen was discovered by Cavendish, in 1766. Its 
name is derived from rSwp, water ; and yfj^mw, I produce. 
It constitutes one-ninth of all water, and part of most 
animal and vegetable bodies. 

Preparation. — We always obtain H from water. 

Isi. By decomposing it with Sodium. Invert a test 
tube filled with water in a dish of the same, introduce a 
pellet of Sodium (Na) under it between the blades of 



Fig. 129. 



Fig. 130. 





scissors, the Na will soon escape and float on the water 



HYDROGEN 



139 



in the tube, setting free H, which will thus fill the latter. 

(Fig. 129.) 

2nd. By passing steam over iron turnings placed in a tube 
and kept at a red heat by a furnace. 

3rd. By decomposing water acidulated with sulphuric 
acid with zinc CH0,S03 + Zii = ZnO.SOg -f H.) 

This operation may be conducted in a "gas bottle," 
Fig. 130, the acid and water (mixed before and allowed 
to cool) being introduced by the long funnel, and the gas 
escaping by the bent tube. Or to make the process self- 
regulating, we may employ the apparatus represented in 
Fig. 131, where the gas, generated by the contact of the 
acid water with the zinc, h, 
if not allowed to escape, col- 
lects in the bell jar, displacing 
the acid solution from the 
zinc, and so stops the action 
until the gas is allowed to 
escape, admitting the liquid 
when the operation recom- 
mences. Such an apparatus, 
made of copper and of large 
size, is very convenient to 
work the oxyhydrogen blow- 
pipe, lime-light, etc. The 
bell in this case had better 
float loose in the outer jar or 
reservoir, and have a capa- 
city of 6 gallons. The charge 

should be a bucket of water and 6 lbs. of oil of vitriol, 
which will yield more than TO gallons of Hydrogen. 
Enough to run a powerful lime-light for two hours. 

4th. By electrical decomposition of water (see page 108\ 
When prepared by this means, the hydrogen has its aftini- 
ties exalted so that it will decompose Sulphate of silver. 
(Smithsonian Reports. 1862, p. 397.) 





iMIIllll illlililllllllilllil'iilllllfl 



140 HYDROGEN. 

Properties . — Hydrogen is a gas, colorless, transparent, 
tasteless, and inodorous ; it has a higher refractive power 
than any other gas; it is the lightest known substance, weigh- 
ing little more than yL as much as air. Density, 0.0692. 
One hundred cubic inches w^eigh 2.14 grains. On account 
of its lightness balloons have been filled with it, and soap 
bubbles so charged rise in the air. It may be collected 
by displacement (see Fig. 130), and poured upwards from 
one vessel into another. 

The extreme rarity of hydrogen was strikingly demon- 
strated in the attempts which were made to condense it 
to a liquid, by great pressure in iron receivers. The hy- 
drogen escaped through the pores of the iron. Ex. If a 
sheet of paper is placed at a little distance from the jet of 
a hydrogen generator, the current of gas will pass directly 
through the paper without altering its direction, and can 
be lighted upon the opposite side of the sheet. 

Hydrogen is combustible, burning with a bluish flame, 
giving little light but intense heat. If a long glass, or 
other tube, is placed around a small jet from which H. is 
burning, the supply of air being thus limited the burning 
will be reduced to a series of slight explosions, which will 
develop a musical sound. This arrangement has, there- 
fore, been called the Hydrogen Organ. 

The Oxy hydrogen Blowpipe, invented by Dr. Robert 
Hare, in 1802, consists of two concentric nozzles with 
other parts, by which a jet of oxygen is introduced into 
the centre of a jet of burning hydrogen. The most com- 
bustible body is thus supplied with the best supporter of 
combustion, and the heat evolved by their union is con- 
centrated in a small space. Its intensity is therefore very 
great. Silver, gold, platinum, etc., are fused and vapor- 
ized, iron, zinc, etc., burned with brilliant effect, and other 
results of a high temperature attained. 

The Lime-light — When the oxy hydrogen flame is di- 



HYDROGEN. 141 

reeled upon a block of lime, this solid serves as a sounding- 
board to its intense vibrations ; and enables them thus to 
develop a light of great brilliancy. For the best effect, 
the pressure on the gases should not be less than f lb. 
per square inch, or 18 inches on a water gauge. If these 
two gases, and H, are mingled in atomic proportions 
(by volume, 1 to 2 ; by weight, 8 to 1) and ignited, they 
will explode with violent detonation, though relatively 
little force. This is well shown by blowing bubbles in 
soapy water with the mixed gases (from a bladder, gas- 
bag, or other receptacle), filling the hand with these and 
firing them. They will make a loud report, but will pro- 
duce no sensation to the hand. The detonation is caused 
by the instantaneous condensation of the vapor of water, 
which is produced by the combination of the two gases in 
contact with cold air. The water occupying, when con- 
densed, a volume HOO times smaller than when it was in 
the state of vapor, leaves a large vacuum. The rushing 
of the air from every quarter with great rapidity into this 
empty space, causes the detonation. 

Compounds of Hydrogen with Oxygen. 

I. Water.— Symbol, HO. Equivalent. 0. Sp. Gr. as 
Yapor, 0.622; as Liquid, 1.000; as Ice, 0.94. 

Properties, (a) Physical. — Clear, colorless, tasteless, in- 
odorous, transparent liquid. Below 32° it freezes into a 
variety of crystalline forms derived from the rhoiubohe- 
dron and six-sided prism. Evaporates at all temperatures, 
and under the usual pressure of the atmosphere boils at 
212°. Reaches its maximum density at about 40°, and 
expands whether cooled below, or heated above, this point. 
In changing to ice, it becomes lighter and increases in 
volume ; and we therefore see why : 

1st. Ice forms only on the top of streams. If water 
followed the same law as almost all other liquids, and 



142 HYDROGEN. 

became heavier in freezing, oar rivers would be frozen 
aolid from bed to surface, the fish they contained destroyed, 
navigation would be interrupted for most of the year, and 
all the heat of a summer sun would scarcely suf&ce to 
make the streams liquid again. 

2nd. A frost, by changing the water contained in the 
cellular tissue of fruit to ice, bursts the delicate cell struc- 
ture and destroys the fruit. 

3rd. Water pitchers, fountains, water-pipes, drains, etc., 
burst in winter time, and frost-stones, or those very porous 
to water, crumble away. 

Its density at 60° is taken as 1.000 ; and with this 
standard the specific gravities of all liquids and solids are 
compared. One cubic inch of water at 62°, weighs 252.456 
grains. A gallon (imperial) contains 10 lbs. Avoirdu- 
pois = YO.OOO grains, or 217.19 cubic inches of water. 

Air dissolved in Water. — The presence of air in water 
which has been exposed to the atmosphere, is readily shown 
by suffering some water to stand quiet for a time in a 
tumbler. Bubbles of gas collect on the inside of the 
glass; accurately, the amount of air is about 3.2 volumes 
to every 100 volumes of water. But this dissolved air 
is much richer in oxygen than atmospheric air, and con- 
tains 33 volumes of oxygen to 100, instead of the 21 
volumes which are found in the atmosphere. This excess 
of oxygen is due to its being more soluble in water than 
nitrogen. Ex. Fishes, which breathe the air dissolved in 
water by means of their gills, die in distilled water. Spring 
waters derive their sparkling taste and invigorating quali- 
ties from the air which they hold in solution. 

Other bodies found in water. — Bain-wafer, in its pas- 
sage from the clouds, carries with it, in solution, all the 
substances which are found in the atmosphere ; such as 
oxygen, nitrogen, carbonic acid, traces of nitric acid, of 
carbonate and nitrate of ammonia. 



NITROGEN. 143 

Spring and well water, which is rain-water drained from 
porous soils or rocks, contains, in addition to the above 
substances, various salts which it has dissolved out from 
the ground ; such as chlorides, sulphates, and carbonates 
of lime, magnesia, soda, potassa, and alumina. A small 
quantity of lime-salts is thought to render drinking-water 
more wholesome, and to aid in building up the bony struc- 
ture of the body. 

(6) Chemical. — Is the best solvent. Perfectly neutral ; 
uniting with most acids and bases. When combined with 
a powerful acid, it supplies the place of a base, and is 
called 6as2C water. In combination with a powerful base, 
it supplies the place of an acid, and is called acid water. 
Bodies combined with water are termed hydrates ; un- 
combined, anhydrous. If the water existing in a crys- 
tallized salt can be driven oif by heat without decompos- 
ing the salt, it is termed water of crystallization ; if it 
cannot, water of constitution. 

II. Binoxide of Hydrogen— HO, = 17. Sp. Gr. 1.453. 

Preparation. — Successive portions of Binoxide of Ba- 
rium are added to Hydrofluoric acid. Ba02+HF=BaF 
-f HO2. The insoluble Fluoride of Barium is removed by 
filtration, and the Binoxide of Hydrogen remaining in the 
liquid, concentrated by evaporation in vacuo. 

Properties. — A syrupy, colorless liquid, with an astring- 
ent and somewhat metallic taste ; bleaching litmus and 
other vegetable colors instantly. At 19° slowly decom- 
posed into oxygen and water; at 212°, with explosive 
haste. Many metals and metallic oxides instantly eftVct a 
like decomposition without themselves undergoing change. 



Sym. N. NITROGEN. Eq. 14. 

Discovered by Dr. Rutherford, in 17t2. Shown to form 

part of atmosphere by Lavoisier, in 1775. Called by the 

French azote (lifeless); from a, privative, and ^o*, life. Its 



144 



NITROGEN. 



name, nitrogen, is from virpov, nitre, and yswdio, I produce. 
Occurs as four-fifths of the atmosphere, and in minei-al and 
animal substances. 

Preparation. — 1st. By burning phosphorus in an in- 
closed portion of air over water. N and 5 -f P = N + 
PO5. 2d. By passing chlorine through aqua ammonia. 
NIfg + 3 CI = 3 HCl + N. 3rd. By heating solution of 
nitrite of ammonia ]S"H,0,N03 = 4 HO -f 2 N. 4th. By 
heating solution of nitrite of potassa with sal ammoniac. 
K0,N03 + :N^H,C1 = KCl + 4 HO -f 2 N. 

Properties. — These are all inert and negative. A gas 
without color, taste, smell, or capability of liquefaction, 
and solidification; density 0.912; does not support com- 
bustion, animal life, or enter, of its own accord, into com- 
bination. 

Mixture of Nitrogen with Oxygen. 

Atmosplieric Air. — Density at 60° taken as 1.000, and 
with this standard the specific gravities of all other gases 
are compared; 100 cubic inches weigh 31.0117 grains. 
Consists, by weight, of 23 parts oxygen, and 77 parts 
nitrogen; by measure, of 21 parts oxygen, to 79 parts 
nitrogen. There is also about one-thousandth part of 
carbonic acid gas, a trace of ammonia, and some vapor, 
varying greatly in quantity with the temperature. 

Regnault's Hygrometer. — The amount of moisture in 
the air, of course, aff"ects its power of taking more, or of 
promoting evaporation. The drver the air, the more 
rapid will be the evaporation taking place in it at equal 
temperatures. We can thus determine the amount of 
moisture in the air by means of this action, as follows. 
We have two thermometers {t t), supported near each 
other, one, however, plunged in a vessel of ether, A, 
through which air is drawn, by means of the aspirator, 



NITROGEN. 



145 



D. The dryer the air, the more the ether evaporates, 
and, therefore (see p. 32), the lower the temperature in 
A (indicated by one thermometer) falls below that of the 
air around indicated by the other. This difference in 
temperatures enables us to judge of the amount of mois- 
ture in the air. 



Fig. 132. 




^a*^ 



The aspirator, D, is used in many cases where we wish 
to produce a steady flow of air through a piece of appa- 
ratus, as in some cases of analysis, the determination of 
the Carbonic acid in the air, etc. 
13 



146 



NITROGEN. 



Fig. 133. 




The Dew Point is that temperature at which the mois- 
ture present in the air is enough to 
saturate it, and would begin to be 
deposited from it as dew. This is 
directly shown by Daniel's Hy- 
grometer. (Fig. 133.) This con- 
sists of a little cryopherous (see page 
31), with a thermometer in one bulb, 
a, and a piece of cloth around the 
other, 6. By pouring ether over 6, 
we so promote evaporation in a, that 
its surface is cooled to the dew pointy 
and we see a misty deposit forming 
on a, which is coated with gold leaf, 
to show this the better. The 
temperature of the thermometer 

in a, at the time this happens, gives us the dew point. 

This temperature is *' high," or near that of the air, in 

damp weather; "low," or much below it, when the air 

is dry. 

Compounds with Oxyg^en. 

Nitrous Oxide, Protoxide of Nitrogen, Laughing Gas 
(NO ; Eq. 22). Sp. Gr. 1.525. Colorless, transparent, 
sweet-tasting gas; liquefiable at 45° under a pressure 
of 50 atmospheres; a candle or phosphorus burns fiercely, 
when plunged in this gas. Its solubility diminishes 
rapidly with increase of temperature ; 100 cubic inches 
of water, at 32°, dissolving 130 cubic inches of the gas; 
and at 15°, only 60 cubic inches. It intoxicates when 
inhaled, and produces insensibility to pain. Prepared by 
heating nitrate of ammonia, NH40,N05 = 4 HO + 2 NO. 

Nitric Oxide, Binoxide of Nitrogen, NO2. Obtained by 
acting upon copper, with dilute Nitric acid. 3 Cu 4- 
4 NO;, = 3 (CuO,N05) + NO2 . Colorless ; in contact with 



NITROGEN. 



141 



air or oxygen is converted into a deep-red gas. whicn is 
the vapor of hyponitric acid, NO4 = NO2 -f- 20. Ex- 
tinguishes a candle, but causes phosphorus to burn 
brilliantly. 

Nitrous Acid — NO3. An orange-red vapor, obtained by 
mixing 4 volumes binoxide of nitrogen, with one volume 
oxygen. NO2 -|- = NO3 . In contact with water, de- 
composed into Nitric acid, and Binoxide of Nitrogen, 
2HO + 6N02= 2(H0, NO5) + 4NO2. On account of 
a like action, it cannot be made to unite directly with 
metallic oxides ; the various nitrites are formed by heating 
corresponding nitrates ; thus, KOjNOs = KOjNOg -f 20, 
oxygen being evolved. 

Hyponitric Acid — NO4, A deep red vapor, at common 
temperatures, at 0°, an orange liquid ; obtained by heat- 
ing nitrate of lead. PbO, NO5 = PbO -f- + NO4. 

Nitric Acid — NO5. A crystalline solid, obtained by pass- 
ing dry Chlorine over well dried Nitrate of Silver, AgO,N05 
+ Cl=AgCl + 0-FN05. 

Hydrated Nitric Acid— H0,N05. The Hydrated acid is 
always meant when Nitric acid is spoken of, because An- 
hydrous Nitric acid is utterly devoid of acid properties. 
It is obtained by heating equal weights of Nitrate of Po- 
tassaandSulphuricacid,K0,N05+2(H0,S03)=K0,S03-f 
HO,S03-fHO,N05. Fig. 134. 

We place, for ex- 
ample, the above 
materials in a glass 
retort, Fig. 134, 
and apply heat by 
means of a spirit 
lamp ; then, as the 
Hydrated Nitric 
acid is liberated, it 
distils over into ^^^P 




148 NITROGEN. 

the glass receiver, kept cool by a stream of water dis- 
tributed on its surface by means of linen or soft paper. 

Besides this compound, which has a specific gravity 
of 1.517, and which consists of 54 parts Anhydrous acid 
united with 9 parts water ; another definite compound 
of the Anhydrous acid with water exists, which has a spe- 
cific gravity of 1.424, and contains 54 parts of the former 
to 36 parts of the latter. Its formula would, therefore, be 
4HO,N05. 

Properties. — The metals placed in contact with Nitric 
acid are oxidized at the expense of the acid, the latter easily 
yielding up a portion of its oxygen to them ; and owing to 
this free liberation of oxygen combustible bodies, such as 
red-hot charcoal in powder, and oil of turpentine when 
heated, burn vividly when Nitric acid is dropped upon 
them. Its chief use, indeed, is as an oxidizing agent. 
Strangely enough, when diluted till its specific gravity is 
1.25, it oxidizes the metals more rapidly than when con- 
centrated. And the same is true with regard to its action 
upon animal and vegetable bodies, such as the skin, wool, 
feathers, and albuminous bodies, lignin, starch, and similar 
substances. 

Uses. — Owing to the rapidity with which Nitric acid 
oxidizes the metals, and the great solubility of the nitrates 
in water, Nitric acid is of invaluable use in the laboratory 
for dissolving minerals, metals, etc. Used to oxidize SO^ 
into SOain the manufacture of sulphuric acid ; when mixed 
with hydrochloric acid, as aqua regia, to dissolve gold, 
platinum, etc. ; to convert starch and sugar into oxalic 
acid; in dyeing ; in engraving on copper and steel — etch- 
ing; in the assay of money ; in polishing and cleaning 
rust from metals and alloys. It converts benzole into arti- 
ficial oil of hitter almonds; it is employed in forming ani- 
line colors, and to transform cotton fibre to gun-cotton. 

Tests. — Bleaches a solution of Indigo in Sulphuric acid 
when boiled with that liquid. Gives a brownish-red color 



AMMONIA. 149 

in contact with a concentrated solution of Protosulphate 
of Iron. 

Compounds of Nitrogen and Hydrogen. 
Sym. NH3. AMMONIA (Volatile Alkali). Eq. 17. 

Sources. — When Nitrogen and Hydrogen come together 
in the nascent state, that is, at the moment when either 
one of them is liberated from some previous combination, 
they unite to form Ammonia. Thus, when lightning flashes 
through the air a small amount of vapor of water, HO, is 
decomposed into its two component elements, H and 0. 
The hydrogen and oxygen, at the moment of their libera- 
tion, unite with the nitrogen of the atmosphere ; the former 
to form Ammonia, NH3 ; the latter. Nitric acid, NO5. Or, 
when iron is exposed to the action of moist air, the iron 
decomposes the water, and unites with its oxygen, to form 
rust or Sesquioxide of iron (Fe^Og), while the Hydrogen set 
free, in the nascent state, combines with the nitrogen of 
the air to form Ammonia: 2Fe + 3HOH-N=Fe203+NH3. 
Ex. Disengagement of Ammonia from rust on mixing the 
latter with caustic potash. 

In the same manner, when Nitric acid acts upon zinc, 
tin, and iron ; thus, 8Zn + 8(HO,N05)=8(ZuO,N05) + 8H, 
the liberated hydrogen has the power, while in the nascent 
state, to decompose another portion of the Nitric acid, and 
form Ammonia: HO,N05-f-8H = GIIO+NH3. 

Lastly, when organic substances decompose — I. Spon- 
taneously — II. By heat alone — III. By heating with 
caustic potassa — the nitrogen and hydrogen combine, in 
the nascent state, to form Ammonia, and in this way is 
derived the fertiliziug property of manure, and the am- 
moniacal liquor of gas-works, which is the commercial 
source of Ammonia. 

Preparation. — I. Fill a matrass half full of equal weight 



150 



AMMONIA. 



of caustic potash and sal ammoniac, and heat the mixture 
gently ; collect over mercury, or by displacement upwards: 

Potassa. Chloride of Ammonium. Chloride of Potassium. Ammonia. Water. 



KO,HO+ NH.Cl = 



KCl 



+ NH3 + 2H0 



Fig. 135. 




II. A slight heat is sufficient to disengage all the Am- 
monia from its solution in water — the liquid Ammonia of 
commerce. 

Liquid Ammonia is prepared by receiving the ammo- 
niacal gas, first in a wash-bottle, filled with 
milk of lime, which is merely the hydrate 
of lime, CaO,HO, diffused through water, 
in order to absorb the Carbonic acid and im- 
purities accidentally present, and afterwards 
in a series of Woulf's bottles. Fig. 135, filled 
with distilled water. The gas enters by 
tube A, bubbles through the water, and 
passes by C into another similar bottle. 
The tube J) serves to prevent the liquid in 
one bottle from being drawn into another in case of a sud- 
den absorption, air instead then entering by this tube. 

Properties. — Ammonia is a colorless gas, which may be 
recognized: 1st, by its sharp, penetrating odor; 2nd, by 
its powerof browning turmeric paper, turning a solution of 
violets green, and cochineal, purple — whence its name of 
volatile alkali; 3rd, by the white fumes or cloud of Chlo- 
ride of Ammonium, NH4CI, which revolve about a glass 
rod previously moistened with Hydrochloric acid, HCl, 
Avhen brought near the slightest trace of free ammonia. 
It extinguishes a burning candle, but burns with a yellow 
flame when introduced in a fine jet into a bell-glass filled 
with oxygen ; it cannot be respired, and produces ophthal- 
mia among workmen exposed to ammoniacal fumes. 
Dropped on the skin, liquid ammonia produces a blister, 



CHLORINE. 151 

and it is consequently employed to cauterize the bites of 
mad dogs. It is decomposed by heat and electricity into 
nitrogen and hydrogen ; by oxygen, with the aid of elec- 
tricity, into water and nitrogen ; a few bubbles of chlorine 
passed into a receiver filled with ammoniacal gas produce 
chloride of ammonium and nitrogen, accompanied by heat 
and light. 

Uses. — Equal amounts of cochineal, ammonia, and water 
boiled together furnish carmine. Many colors may be 
made, and still others, such as crimson and Prussian blue, 
may be modified by ammonia. It is largely employed by 
scourers to take out grease spots, and to restore colors 
changed by acids ; by the manufacturers of artificial pearls 
to prepare the Essence d^ Orient. This is obtained by hold- 
ing in suspension in liquid Ammonia the minute 'scales of 
the Blay-fish, and is used by injecting it into pearl-like glo- 
bules of glass. The scales attach themselves to the inside 
walls of the hollow glass drops, and sparkle like Indian 
pearls. 

In medicine, besides its internal and external application 
to the bites of serpents, stings of insects, etc., it is used in 
the treatment of hoven. This disease arises in sheep and 
cows from eating green apples and wet grass, which gene- 
rate so large a quantity of Carbonic acid in the intestines, 
as to cause death in a short time. The ammonia absorbs 
this gas, forming the salt, Carbonate of Ammonia. 



Sym. CI. CHLORINE. Eq. 35.5. 

Discovered by Scheele in 1144. Its true character pointed 
out by Gay Lussac and Thenard in 1809. Its nnme given 
by Sir H. Davy, from z'^^po^, yellowish-green, color of 
younir grass. Chief source in nature, common salt. 

rreparation. — 1st. Heating in a flask sUgJithj diluted 
hydrochloric acid with binoxide of manganese, 2IlCl-f- 



162 



CHLORINE. 



MnO.,= MriCl+2HO + Cl (Fig. 136); 2nd. Heating com- 
mon Salt, Binoxide of Manganese and Sulphuric acid, 
NaCl + MnO, + 2(HO,S03)=:Cl+NaO,S03 + MnO,S03 + 
2H0. Best collected by displacement, as Fig. 136, or if 

Fig. 136. 




for any reason over water cold water is better than hot, 
care being taken to let it pass through as little as possible. 

Properties. — Chlorine is a gas of a greenish-yellow 
color, an acrid taste and disgusting suffocating smell. It 
becomes liquid under a pressure of 4*5 atmospheres at 60°. 

This gas has a strong afi&nity for the metals, so that 
many of them will inflame if thrown into it. Thus, for 
example, is it with Antimony, Arsenic, Potassium, etc., 
in powder, or Dutch gold leaf (made of brass). (Fig. 137.) 
Its affinity for Hydrogen is also very great ; mingled with 
that body it will combine slowly in diffused light, but ex- 
plosively in the direct rays of the sun, electric lamp, etc. 
To this attraction it owes its efficiency as a bleaching 
agent. By combining with and removing the Hydrogen 
from organic coloring matter it destroys it, and thus 
bleaches or removes all such substances. 



CHLORINE. 



15S 



Bleaching. — In practice, goods to be bleached are first 
well washed and boiled in water with strong alkalies, 



Fig. 137. 



to remove all grease, etc. ; then they 
are saturated with chloride of lime 
mixed in water; then they are im- 
mersed in water containing a little 
sulphuric acid, which liberates chlo- 
rine from the chloride of lime con- 
tained in the cloth among its fibres. 
This efi'ects the bleaching most per- 
fectly. The cloths must lastly be 
washed for a long time in fresh water, 
to remove all trace of acid. To re- 
move stains from linen or cotton goods, 
in the small way, Chloride of Soda 
(Labarraque's Solution) or Chloride 
of Potash (Javelle water) which may 
be obtained from any apothecary, are 
very useful. The stained cloth should 
be immersed in the solution ; a little 
boiling water added, if necessary, or, 
in obstinate cases, the whole placed in 
the sun for some hours. The article 
should be thoroughly rinsed with fresh 
water before it is allowed to dry. Col- 
ored fabrics cannot be thus treated, as their color would 
disappear with the stain. 

Woollen cloths are not bleached with chlorine, but with 
fumes of burning sulphur, i. e. Sulphurous acid, SO... 

It is by an action similar to the above that Chlorine 
acts as a deodorizer, breaking up the offensive gases by 
removing tlieir hydrogen or like clomont. A little chlo- 
ride of lime thrown under a floor will thus alVord entire 
relief from the "attacks" of a dead mouse. 

Te&t — We recognize free Chlorine bv its smell, color, 




154 CHLORINE. 

heavy fuivie with ammonia, curdy white precipitate with 
nitrate of silver, and bleaching of organic colors. 

Compounds of Chlorine and Oxygen. 

HypochloroilS Acid — CIO. An orange-yellow liquid, ob- 
tained by passing Chlorine over red Oxide of Mercury, 
2HgO -f 2C1 = HgCl.HgO 4- CIO. Readily decomposed 
by heat into oxygen and chlorine. It bleaches powerfully, 
and combines with the alkalies to form hypochlorites, pos- 
sessing the same property. 

CMorous Acid — CIO3. A greenish-yellow gas, obtained 
by heating a mixture of Arsenious acid, Chlorate of Po- 
tassa, and Nitric acid. The nitric acid yields up some of its 
oxygen to the arsenious acid ; nitrous acid is formed, and 
afterwards converted back again into nitric acid by oxygen 
given off from the decomposed chloric acid. Thus AsOa 
-f H0,N05= ASO5 + H0,X03; and HO.XOs + K0,C105 
= KO.X05+C103+HO. 

Hypochloric Acid — CIO4. A deep-yellow explosive gas, 
evolved by heating concentrated Sulphuric acid with 
Chlorate of potassa^ 3(KO,C105)-f 3(HO,S03)=2C10,-f 
ClO, + 3(KO.S03) + 3H0. 

Chloric Acid — CIO5. Obtained by boiling Chlorate of 
Potassa with Hydrofluosilicic acid. 

Test. — The chlorates evolve pure oxygen when heated. 

Perchloric Acid — CIO7. Shown above as one of the 
products in formation of Hypochloric acid. 

Compounds of Chlorine with Hydrogen. 

Hydrochloric Acid— H CI. 

Preparation. — 1st. When equal volumes of Hydrogen 
and Chlorine are exposed to the direct sun-light they unite 
explosively. 2nd. From Sulphuric acid and common Salt. 
XaCl -f H0,S03 = XaO,S03 -f HCl. 

Properties. — A powerfully acid gas, with an intense at- 



BROMINE. 155 

traction for water. The latter absorbs 418 times its bulk 
of this gas to form the liquid known as Hydrochloric acid. 
Unites with metals, forming chlorides, with liberation of 
hydrogen, and with metallic oxides, to form chlorides and 
water. 

Uses. — It is a very delicate test for the salts of silver 
and for ammonia. It is employed in the arts for preparing 
Labarraque^s solution, Javelle waUr, bleacJiing powder, 
for the extraction of gelatine from bones, etc. It is used 
alone, or in aqua regia, to dissolve very many minerals, 
and to prepare the metallic chlorides. 

Chloride of Nitrogen — NCI3. A fearfully explosive oily 
liquid, formed by passing chlorine into a solution of sal 
ammoniac. 



Sym. Br. BROMINE. Eq. 78.26. 

Discovered by M. Balard in 1826. Named from )3pw/io?, 
a disgusting smell. Found in sea-water, especially of the 
Dead Sea, mineral springs, and native bromides. Sp. Gr. 
2.96. 

Preparation. — Bittern, which is the mother-liquor of sea- 
water, after the less soluble salts have been separated by 
crystallization, contains various bromides. These are de- 
composed by a stream of chlorine passed through the 
liquid, and the bromine, set free, dissolves in a quantity 
of ether agitated with the bittern thus treated. 

Properties. — When separated by a complicated process 
from the ether, Bromine is a deep-red, volatile liquid, of a 
very suffocating and offensive odor; freezes at about 19'^ 
and boils at 145°; bleaches many vegetable colors ; unite;- 
directly with many of the metals, sometimes with ignition, 
forming bromides. Bromide of silver is considerably em- 
ployed in photography. Combines with Hydrogen to form 
HyUrobromic acid, 11 Br. 

Test. — Starch is colored yellow by free broniiiu'. 



166 IODINE — FLUORINE. 

Sym. I. IODINE. Eq. 126.36. 

Discovered in 1812 by M. Courtois. Named from iqSj^j, 
violet-like. Found in sea-water, sea-weeds, some mineral 
springs, and as iodides of lead and silver. Sp. Gr. 4.94. 

Preparation. — By gently heating the bittern from kelp, 
which contains Iodides of Sodium, Magnesium, etc., with 
Sulphuric acid and Binoxide of Manganese. Thus, KI + 
MnO, + 2 (H0,S03) = I + KO.SOs +MnO,S03+2HO. 

Properties. — At ordinary temperatures a metallic bluish- 
black solid, having the form of rhomboidal scales or taper- 
ing octahedrons; at 225° it changes to a liquid, and at 
347° to a rich intense violet vapor. It is but slightly 
soluble in water, which dissolves about O.OOY of its weight 
at ordinary temperatures ; in ether and alcohol it dissolves 
readily and forms dark reddish-brown liquids. Its chem- 
ical affinities are like those of chlorine and bromine, but 
being more feeble it is displaced from combination by 
these two metalloids. It unites with hydrogen to form 
Hydriodic acid, HI, and with oxygen to form Iodic acid, 
IO5, and Periodic acid, IO7, but none of these compounds 
are of practical importance. 

Test. — It unites with starch, in the presence of water, 
to form a beautiful blue iodide of starch. This iodide 
loses its color at a temperature of 165°, and recovers it 
again on allowing the liquid to cool. 

Uses. — Iodine alone, or in combination with potassium, 
is a remedial agent for goitres and scrofula. The iodides 
of potassium, sodium, ammonium, and cadmium are em- 
ployed in photography to iodize the collodion. 



Sym. F. FLUORINE. Eq. 18.7. 

Discovered by Sir. 11. Davy, but has never as yet been 

isolated in such a state as to admit of satisfactory inves- 



FLUORINE. 167 

tigation. It derives its name from fluor spar m which it 
is chiefly found ; specific gravity, 1.32 (theoretical). 

Hydrofluoric Acid — HF. A highly acid gas obtained by 
acting on fluor spar (fluoride of calcium) with Sulphuric 
acid, CaF4-HO,S03=CaO,S03 + HF. 

Use. — It acts powerfully on all siliceous matters, and is 
therefore employed in etching glass. For this purpose the 
plate, or other object to be etched, is coated with wax; 
the design to be produced is scratched through this. Some 
Fluor spar in coarse powder is then spread in a shallow 
leaden dish (see Fig. 138), moistened with oil of vitriol 
warmed with a spirit 

lamp. As soon as ■^^°* ^^^' 

fumes comes off the 
lamp is removed, and 
the plate set face 
downwards for a 
minute or two upon 
the dish. The ex- 
posed parts of the 

glass are corroded by the fumes and acquire the appearance 
of ground glass, thus showing the design upon the smooth 
glass when the wax has been removed by scraping and 
rubbing with turpentine. Thermometer tubes, chemical 
bottles, etc., are often marked in this way. Plates of glass 
on which frost-like crystals have been formed, by spread- 
ing them with gum-water containing in solution, Nitre, 
Sulphate of Copper, or the like, may be thus etched so as 
to form beautiful objects for the magic lantern, or glass 
goblets may be permanently frosted by this process. A 
solution of HF in water etches likewise, but with a 
smooth surface. 
14 




158 CARBON. 

Sym. C. CARBON. Eq. 6. 

Carbon occurs in three forms : 

1st. Diamond, whose name is a corruption of adamant 
(from a, privative ; and Sa^ua'w, / subdue), invincible. Hard- 
est of all substances, cannot be cut except by its own dust; 
but scratches all other minerals and metals. Sometimes 
colored, but usually limpid ; infusible at all temperatures; 
combustible at a white heat with formation of Carbonic 
acid gas ; of a high refractive and dispersive power ; feebly 
phosphorescent when brought into a dark room after ex- 
posure to light. It crystallizes in octahedra and tetra- 
hedra, oftentimes with curved faces. It is probably of 
vegetable origin. 

Uses. — As an ornament, cut as a rose or hrilliant; the 
former having the under surface flat, and the upper 
elevated, en dome, without table, and reflecting light from 
24 facets ; the hrilliant is cut into symmetrical facets on 
both lower and upper faces. 2nd. For cutting glass, for 
delicate pivot-rests, and as a grinding and polishing 
powder. 

2nd. Graphite or Plumbago. — A very friable substance, 
soft and greasy to the touch, and of a metallic leaden- 
gray lustre. It is largely worked at Ticonderoga, New 
York, and at Brandon, Yermont. It is sometimes found 
in brilliant six-sided spangles, which may also be arti- 
ficially produced by dissolving charcoal in melted iron. 

Uses. — Lead-pencils ; mixed with fire-clay, it is made into 
"black-lead" crucibles for melting gold, silver, etc.; it is 
rubbed over iron-castings to preserve them from rust — 
stove-polish; to relieve the friction of carriage axles, wheels 
of machinery, and even of clocks; to polish gun-bullets; 
smeared over the wax medals in an electro-plating bath 
to cause the deposition of gold and silver upon their 
surface. 



CARBON. 159 

3rd. Amorphous Carbon. — In consequence of its infusi- 
bility carbon presents itself in a variety of aspects accord- 
ing to the structure of the body from which it was formed 
and the manner of its preparation, viz. : 

(a) Metallic Carbon. — A metallic coating formed by 
the contact of the carburetted hydrogen gases produced 
in the distillation of coal with the red-hot sides of the 
retort. It is an excellent material for the carbon points 
of the electric light, and for the positive pole of Bunsen's 
battery. 

(&) Charcoal is formed by burning stacks of wood which 
are covered over with leaves and dirt to prevent a free 
access of air. The charcoal of light woods, such as black 
alder and willow, is largely consumed in gunpowder. As 
a powder, charcoal is used for polishing copper and bronze; 
as a dust, it is sprinkled over meats to preserve them from 
decay ; in lumps, to absorb noxious gases. So the charring 
of the ground end of fence posts secures them from rot. 

(c) Coke is obtained by distilling off the water, tar, and 
gas from bituminous coal ; 100 tons of the latter affording 
50 or 60 tons of coke. It produces a greater heat than 
any other fuel, except Anthracite, and is largely employed 
in blast furnaces, forges, etc. 

(d) Lampblack is condensed upon the sides of chambers, 
in which resins, fats, etc., are burnt with an insufficient 
draft of air. It is employed in painting; mingled with 
two-thirds its weight of clay, to form black drawing-cray- 
ons; intimately mixed with dry linseed-oil to make an 
indelible printer's ink. Manuscripts, written in an ink 
composed of lampblack and gum-water, have been exhumed 
at Herculaneum and Pompeii, still perfectly legible. 

(e) Animal charcoal is made by burning bones in close 
vessels. It serves as an antidote to vegetable and animal 
poisons, but its principal use is to refine sugar. After a 
while it loses its power of decolorizing syrup ; but it may 



160 COMPOUNDS WITH OXYGEN. 

be revivified by drying-, saturating with Hydrochloric acid 
^as, washing, and reburning. (See Franklin Institute Jour- 
nal, Y. 49, p. 250.) Ex. A rich solution of indigo, filtered 
through animal charcoal, loses its color entirely. 

Compounds with Oxygen. 

Carbonic Oxide— CO. Sp. Gr. 0.9*72. 

Preparation. — Heat 1 part of Ferrocyanide of Potassium 
with 10 parts of sulphuric acid. KaCeNgFe + 6(H0, 
SO3) + 6H0 = 6C0 + 2(KO,S03) + FeO.SOs + 3(NHA 
SO3) 

Properties. — A colorless, inodorous, poisonous gas ; ex- 
tinguishes flame, but burns itself with a purplish blue 
flame, easily extinguished. Seen in coal fires where there 
is a lack of air. 

Carbonic Acid — CO2. (Fixed air, choke-damp.) Sp. Gr. 
1.52Y. 

Sources. — Combined with lime, as limestone, forms one- 
seventh of the solid crust of the earth's surface. United 
with iron, copper, zinc, etc., forms many valuable ores. 
Constitutes one-thousandth part of our atmosphere. 

Preparation. — By decomposing a carbonate by any 
strong acid. Ex. NaO,C02 -|- H0,S03 = Na^SOa + HO 
-f CO,. 

Thus we place in a vessel such as A (Fig. 139) some 
common washing soda (Carbonate of Soda), and pour 
upon it dilute Sulphuric acid. The gas is then freely 
developed, and may be collected by displacement. This 
gas is also produced in all ordinary cases of combustion 
and in respiration. The amount of CO2 exhaled by a 
man in twenty-four hours, is about 26-J ounces. This 
would give for the inhabitants of the world, about 820,000 
tons per day. Fortunately, plants reverse this action. 

Properties. — The weight of this gas is very notable. It 
may be poured from one vessel to another and weighed 



CARBON. 



161 



readily on a large scale in a grocer's paper-bag, or in a 
wooden bucket. 

Many of its properties may be well exhibited by arrang- 
ing an artificial grotto, Fig. 139, and allowing the gas 



Fig. 139. 




from the bottle, A, to flow into it. This will settle like 
water at the lower part, and a taper will burn within 
until lowered beneath the surface of the gas. A little 
slide being then opened in the side of the box, the gas 
may be drawn off into vessels, poured from them over 
candles so as to extinguish them, etc. 

It directly interferes with and prevents combustion. It 
has therefore been used, by Sir Goldsworthy Gurney, in 
fire-engines which pour Carbonic acid instead of water 
upon a burning building, and for putting out fires in burn- 
ing mines. Does not support respiration ; and when formed 
in mines by explosions of fire-damp, it is the choke-damp 
so fatal to miners. Under the influence of light, it is 
decomposed in the leaves of plants. The carbon being 
essential to vegetable growth, is retained by the plant; 
while the oxygen is returned to the atmosphere, in order 
that animal life may be sustained. It is soluble in water, 
and when held in solution under pressure, makes soda- 
water. 

Liquid Carbonic Acid. — Under a pressure of 40 atmos- 
14* 



162 CARBON. 

pheres, or 600 lbs to the square inch, Carbonic acid gas is 
condensed to a colorless liquid. 

Solid CarbOBic Acid. — When a jet of this liquid is thrown 
into a metallic receiver filled with holes, the vessel is seen 
to fill rapidly with a flaky snow. This is solid Carbonic 
acid, formed by the great cold — about 150° — given out in 
the very rapid evaporation of part of the liquid Carbonic 
acid. By mixing solid Carbonic acid with ether, and evap- 
orating under the receiver of an air-pump, a temperature 
as low as-166° F. is produced. This mixture, as it were, 
burns the hand if placed upon it, and causes active in- 
flammation. 

Test. — Lime-water is so delicate a test that it is rend- 
ered cloudy by blowing the air from the lungs through 
it for a very short time 

Compounds of Carbon with Hydrogen. 

Protocarburetted Hydrogen — C2H4. (Light Carbu- 
retted Hydrogen). Exists native, as fire-damp in coal- 
mines, and the inflammable air of marshes — marsh-gas. 
Prepared by heating 4 parts of acetate of soda (which 
must be first dried), 4 parts of caustic potash, and 6 parts 
quicklime, powdered and mixed in a strong glass flask, 
2cNaO,C,H303) + KO,HO + CaO,HO = 2(NaO,C02) + 
KO, CO2+ CaO, CO2+ 2 C2 H4. 

Properties. — A colorless, transparent gas. Sp. Gr. 0.555. 
Extinguishes flame, but burns itself with a pale yellow 
flame ; mixed with air and lighted, explodes. 

Bicarburetted Hydrogen — C4H4. Sp. Gr. 0.98. Also 
called Heavy Carburetted Hydrogen and defiant Gas. 

Preparation. — One measure of alcohol is heated with 3 
ofsulphuricacid,CJT60, + 2(HO,S03)=2(HO,S03) + 2HO 
-f C^H^. To avoid frothing, we pour sand into the flask 
till all the liquid is absorbed by it. 

Properties. — A colorless gas, with a sweet, alliaceous 



COMPOUNDS WITH HYDROGEN. 



163 



odor; soluble in about 12 times 
its bulk of cold water; liquefi- 
able under great pressure ; not 
a supporter of combustion. Very 
inflammable, burning with a 
w^hite luminous flame. Combines 
with chlorine to form Dutch 
Liquid, C^H.Cl.,. 

Remark. — The two preceding 
gases are the principal constitu- 
ents of coal-gas. Prepared by 
distilling bituminous coal in 
large iron retorts ; purifying 
the gases evolved by passing 
them through vessels filled with 
spray of water (which absorbs 
their ammoniacal impurities), 



Fi-. 140. 




Fig. 141. 




164 CARBON AND NITROGEN. 

and through vessels containing moist lime (which absorbs 
the sulphur and carbon compounds), and lastly, storing 
them in large, self-adjusting gas holders; whose principle 
is illustrated by the smaller apparatus figured in the cuts. 
Fig. 140, and Fig. 141. As the gas flows in, the inner 
drum rises, giving space ; as it escapes, this sinks, so 
diminishing the capacity of the vessel. 

Compound of Carbon with Nitrogen. 

Cyanogen— C^N or Cy. Sp. Gr. 1.82. 

Source. — Cyanogen is formed, in combination with 
potassium, by heating organic substances containing 
nitrogen, such as fibrine, gelatine, skins, etc., with 
potash. 

Preparation. — Obtained by heating Cyanide of Mercury. 
HgC,N = Hg-f C,N. 

Properties. — A colorless, soluble gas ; liquefiable by a 
pressure of four atmospheres. Its odor resembles that 
from bitter almonds. Burns with a dark blue flame fringed 
with purple. In chemical properties, it must be classed 
with chlorine and bromine ; uniting, like them, with hydro- 
gen to form an acid, and with the metals to form salts. 
It was the first one, among many compound bodies since 
discovered, which was found to play the part of an ele- 
ment ; and the discovery of this " Compound Radical," as 
such bodies are called, by Gay Lussac, in 1814, greatly 
simplified modern chemistry. 

Uses. — Its combination with hydrogen, Hydrocyanic, or 
Prussic acid, HCy, is a fearful poison, whose proper anti- 
dote is chlorine or ammonia, cautiously inhaled. Diluted, 
however, with 50 times its weight of water, it is employed 
to allay nausea, and as a lotion in skin diseases. Cyanide 
of Potassium, KCy, energetically dissolves the cyanides 
of gold and silver, and forms with them double cyanides, 
which constitute the gold and silver baths in Electro- 



BORON. 165 

plating. Alone, Cyanide of Potassium is excellent foi 
fixing Collodion Positives. 

Compound of Carbon with Sulphur. 

Bisulphide of Carbon — CSa, Sulphocarbonic Acid. Sp 
Gr. 1.272. 

Preparation. — Prepared by passing sulphur vapor over 
ignited charcoal and condensing the result by cold. A 
transparent, colorless liquid, insoluble in water, of most 
disgusting smell. 

Uses. — To dissolve sulphur, phosphorus, many resins, 
oils, etc. Owing to its great refracting and dispersive 
power, it is employed in prisms of the spectroscope and 
other optical instruments ; in the construction of thermom- 
eters for measuring intense cold, since it cannot be frozen ; 
along with tallow and phosphorus, as a substitute for 
black-lead in electro-silvering large medals, etc. To re- 
move grease-stains. 



Syin.B. BORON. Eq. 10.9. 

Discovered by Davy, 1807. 

Preparation. — The double fluoride of boron and po- 
tassium is heated with an equal weight of potassium. 
KF,BF3 -f 3K = 4KF + B. 

Modifications. — 1st. As thus obtained, Boron is an 
amorphous olive-green powder, which burns when heated 
in the air to a point below redness, forming Boracic acid. 
In this condition it corresponds to charcoal. 

2nd. As octahedra; which are very hard, highly re- 
fracting; fusible only under intense heat, and in all respects 
like Diamond. 

3rd. As scaly, hexagonal plates, rosemblino; Graphite. 

Compound with Oxygen. 
Boracic Acid— BO3. Sp. Gr. 1.8. 
Source. — Discharged from small craters or soJJumi 



166 SILICON. 

along Tvith sulphuretted hydrogen and steam, into the 
bottom of the Tuscan lagunes. The waters of these 
lagunes are evaporated until the Boracic a<jid which they 
hold in solution crystallizes out. The requisite heat is 
derived from the vapors of the sofi&oni, which are con- 
ducted by stone passages beneath the evaporating pans. 

Preparation. — Decomposing Biborate of Soda with Sul- 
phuric acid, NaO,2B03 + HCSOg -f Aq = NaCSOa -f 
2B03 + HO + Aq. 

Properties. — It contains 3 equivalents of water of crys- 
tallization, separable from the acid at a red heat ; tinges 
flames green, and combines with bases to form borates, 
the most important of which is biborate of soda or borax. 
The latter is also imported largely from Thibet, under the 
name of tincal. 

Uses. — Borax is employed in medicine, enters into the 
composition of a glaze for stoneware, is used as a flux in 
blowpipe analysis, and in welding and soldering. 



Sym. SL SILICON. Eq. 21.35. 

Discovered by Berzelius, 1824. 

Source. — Exists in three forms, like Carbon and Boron : 

(a) As obtained in the above reaction, a dark-brown pow- 
der, burning, when heated in the air, to Silicic acid, SiOj, 

(b) Resembling diamond, (c) Graphitoidal. 
Preparation. — Prepared like Boron: KF,SiF3-f3K= 

4KF+Si. 

Compound with Oxygen. 

Silicic Acid, Silex, Silica, SiOg. Sp. Gr. 2.66. 

Source. — Forms 45 per cent, of the solid crust of the 
globe, occurring pure as quartz (rock crystal) ; almost pure 
in chalcedony, flint, agate, and carnelian ; chief ingredient 
of sandstone rock. Combined as a mineral acid with 
almost every known base, it forms a vast variety of ores 



SILICON. let 

and rocks. It is found in small quantities in the ashes of 
nearly all vegetables. 

Preparation. — The process consists of two parts : {a) 
equal quantities of powdered glass and fluor spar are heated 
with sulphuric acid ; the hydrofluoric acid generated from the 
fluoride of calcium and sulphuric acid decomposes the silicic 
acid in glass, forming gaseous tei-Jiuoride of silicon, SiFg; 
(6) This gas is made to bubble through a large amount 
of water in another vessel ; the water is decomposed by it, 
and hydrofluosilicic acid, 3Hr,2SiF3, together with gelati- 
nous silica is formed ; thus, (a) 9CaF + 9HO,S03=9HF-f 
9CaO,S03, and 9HF + 3Si03=9HO + 3SiF3. (6) 3SiF3 + 
3HO=Si03 + 3HF,2SiF3. 

Properties. — (a) Physical. Anhydrous Silicic acid is a 
snowy-white, tasteless solid, infusible in the fiercest blast 
of a furnace, but can be spun out before the oxyhydrogen 
blow-pipe into very fine threads. 

(6) Chemical. Silicic acid exists in two entirely different 
forms : — 

1st. Insoluble Silica. Anhydrous Silicic acid, after hav- 
ing been heated to redness, is insoluble in water and all 
acids, except hydrofluoric. Fused with the alkalies or 
their carbonates, it is converted into 

2nd. Soluble Silica. In this way the chemist is able to 
attack and dissolve with acids a great number of siliceous 
minerals. 

Though Silica is a very feeble acid, yet when heated 
with compounds of the strongest acids, as the sulphates, 
it can expel them on account oi. its non-volatility, or fixed- 
ness. 

Varieties. — Crystallized in ice-like hexagonal prisms, it 
is known as rock crystal; stained by nickel an apple- 
green, chrysoprase ; by sesquioxide of iron, clear yellow 
and bright red, /aZse topaz and caimelian : by sesquioxide 
of manganese, violet, amethyst. When the color is centred 



168 SULPHUR. 

in blood-red spots, it is known as blood-stone, when grouped 
in concentric layers of varying tint, as sardonyx, 3Iocha 
stone, ribaiid jasper, and the Lydian or touch-stone. 
When the Silica occurs as a hydrate, and sends from its 
interior broken beams of light, hyacinth red, and golden 
and fiery crimson, it is called girasol and noble opal. 

Uses. — As a jewel ; in irregular conchoidal masses, gun- 
flints ; as agate rests for the knife-blades of delicate 
balances ; as tripoli — a granular Silicic acid, the remains 
of shell-fish — for polishing. In the form of grain or sand, 
in all glass-making and pottery ; as sand compacted by a 
natural cement of lime or silica, an invaluable building 
material — sandstone, etc. 



Sym. S. SULPHUR. Eq. 16. 

Sources. — Found native in the volcanic districts border- 
ing upon the Mediterranean, especially at the Solfatara 
near Naples, and at Mt. Etna; in South America, India, 
and the volcanic islands of the Pacific. Many valuable 
ores are sulphides, such as cinnabar, smaltine, kupfer- 
nickel, pyrites, and blende ; and as a sulphate, in gypsum, 
heavy spar, and celestine, it no less abounds. In combi- 
nation with hydrogen, it gives to many mineral waters 
their ofi'ensive smell and taste ; it is present in oil of mus- 
tard, garlic, assafoetida, and onions ; and accompanies the 
petroleum which flows from Canadian wells. 

Preparation. — Purified from the blue clay, gypsum, or 
rock salt, in which it is found, by sublimation. It is di- 
morphous, and has 

Modifications. — 1st. As found native, or as obtained by 
evaporating a solution of Sulphur in Bisulphide of Carbon, 
it is a semitransparent, amber yellow, rhombic octahedron 
In this, which is its stable form, it has a sp. gr. 2.05, and 
fuses at 239°. 



SULPHUR. 169 

2nd. Crystallizes from fusion in transparent, brownish- 
yellow, oblique rhomhic prisms ; sp. gr. 1.98 ; fuses at 248*^. 
Unstable, shortly becomes opaque, and crumbles into the 
first form. 

3rd. Heated above 482°, and suddenly cooled, assumes 
the condition of an amber-colored elastic solid. But even 
its amorphous form is unstable, and after a while becomes 
brittle by crystallizing into octahedra. A red and black 
modification likewise exist. 

Properties. — Burns at 460°, and forms Sulphurous acid ; 
sublimes into flowers ; when heated and run into moulds 
forms Boll-sulphur or brimstone. Combines readily with 
Chlorine, Bromine, and Iodine ; has such an affinity for 
metals that many of them, in powder, will burn vividly, 
if heated in its vapor, and form sulphides or sulphurets. 

Uses. — It is applied in taking impressions, and in making 
moulds or medals ; in vulcanizing India-rubber ; for 
matches ; constitutes 10 per cent, of gunpowder. It was 
selected as a lubricant for the axles of the car on which 
the monster Fort Pitt cannon was transported from Pitts- 
burg to Philadelphia. It is prescribed for constipation, 
gout, asthma, etc.; externally as an ointment for cuta- 
neous diseases, and both internally and externally for 
chronic rheumatism. 

Compounds with Oxygen. 

Sulphurous Acid— SO,. Sp. Gr. 2.24t. 

Pre'paration. — By burning Sulphur in Oxygen, or by 
heating Sulphuric acid with copper, Cu + 2(110, SO3) = 
CuO,S03+ SO, -f 2110. 

Properties. — A suffocating, irrespirable gas; becomes 
liquid at 14°; water absorbs 44 times its bulk of this gas, 
which must therefore be collected over mercury. May be 
combined with many bases by being transmitted through 
water holding the metallic oxide or carbonate. 
15 



no SULPHUR. 

Uses — Owing to the property which Sulphurous acid 
possesses of bleaching most coloring matters, it is largely 
employed to whiten silk and wool. Chlorine cannot be 
employed to bleach these two fabrics, because it tinges 
them yellow. The moistened goods are simply thrown 
over rails in large rooms, where Sulphur is kept burning. 
To bleach isinglass (gelatin) and the straw for bonnets, 
hats, etc. ; to take out fruit-stains from pocket-handker- 
chiefs, dresses, etc. ; to free infected places from miasma 
and infection, and to purify lazarettos. In casks, it pre- 
vents the wine they contain from turning into vinegar : it 
is sufficient to burn in them a little sulphur. Sulphurous 
acid in combination with Soda, as Sulphite of Soda, NaO, 
SO2, is employed, under the name of antichlorine, to com- 
bine with the excess of chlorine, or hypochlorite of lime, 
which has been used in bleaching paper-pulp, and, by 
neutralizing it, prevent the evil effects which would ensue 
from an overdose of chlorine. 

Sulphuric Acid — SO3. Distils over from fuming Nord- 
hausen acid as a white, silky solid, devoid of acid prop- 
erties, HO,2S03= HO -f 2SO3. Possesses an intense 
affinity for water, and when combined with it as a hy- 
drate forms what is generally known as concentrated oil 
of vitriol, or Sulphuric acid, HOjSOg. Sp. Gr. 1.84; melts 
at 65°. There are four hydrates. 

1. Dihydrate — HO,2S03. Nordhausen Sulphuric acid, 
formed by distilling dried sulphate of iron. 

2. Monohydrate — H0,S03. Formed by concentrating 
in platinum stills the weak brown acid (see next page). 
An intensely acrid, powerful acid ; destroys organic sub- 
stances by its strong attraction for the elements of water ; 
for the same reason very valuable as a desiccating agent. 
Sp. Gr. 1.845. Freezes at —30°; boils at 640°. 

3. Bihydrate — ^RO,^0^. Obtained when sufficient 
water has been added to the Monohydrate to reduce its 



SULPHUR. 171 

density to l.'TS. Crystallizes in beautiful rhombic prisms 
at 47°; boils at 435°. 

4. Terhydrate — SB.O,^Oi. By evaporating at 212° in 
vacuum a still more dilute acid till it ceases to lose weight. 
Sp. Gr. 1.63 ; boils at 3480. 

Preparation. — Process of the Leaden Chambers. Con- 
sists in, 1st. A deoxidation of Nitric acid by Sulphurous 
acid, SO, + H0,N05 = H0,S03 + NO4. 2d. A union of 
the Hyponitric acid so formed with 2 equivalents of sul- 
phurous acid and an indefinite quantity of water, to form 
a thick crystalline compound (N04+2S024-Aqua). 3d. 
An immediate decomposition of this compound in contact 
with steam, and the formation of 2 equivalents of sul- 
phuric acid, which remain in solution, and 1 (([uivalent 
of Binoxide of Nitrogen; thus, NO4 -f 2S02+Aq.=:NOj 
-f2(HO,S03)4-aq. 4th. A union of this NO2 with 20 
to form NO4 again. The NO4 so formed repeats the 
second step; more NO, is formed, and so the operation 
continues by the carrying, on the part of the Binoxide 
of Nitrogen, of Oxygen to the Sulphurous acid. 

The very dilute acid so formed is concentrated to a den- 
sity of 1.72 by evaporation in leaden pans, and called 
Brown acid ; and by further concentration in vessels of 
platinum becomes oil of vitriol of commerce, whose den- 
sity should be 1.845. 

We can demonstrate this action on the small scale very 
completely with the apparatus shown in Fig. 142. Into 
the large glass vessel, F, we pass Sulphurous acid from 
the flask, A, and Nitric oxide (which, with the air present, 
at once forms NO4) from the gas-bottle, B. The reaction 
soon commences, and F becomes coated with silky crys- 
tals. We then pass in steam from C, when these crys- 
tals are decomposed, and red fumes reappear; then more 
Sulphurous acid from A is admitted, and air is forced in 
through D, while excess of gas escapes by tube E, leading 
10 a chimney. 



It2 



SULPHUR. 



Uses. — In tLe manufacture of Carbonates of Soda, Nitric 
and Hydrochloric acids, Chlorine, Phosphorus, Alum, Cop- 
peras, Ether, and many other chemicals; in making can- 
dles, in refining coal-oil, etc. 

Fig. 142. 




Test. — Gives a white precipitate with Chloride of Ba- 
rium, BaCl -f H0,S03 =BaO,S03 -f HCl. 



Other Compounds of Sulphur and Oxygen, 

Not important, except Hyposulphurous acid, S2O2. This 
is employed in combination with soda, as Hyposulphite of 
Soda (NaOjSjOa), io fix the photographic image; that is, 
to decompose the Chloride of Silver which has not been 
affected by the light while in the camera, and which if 
allowed to remain on the paper, after removal from the 
camera, would darken and obliterate the picture. The 
result of this decomposition is Hyposulphite of Silver 
and Chloride of Sodium, both of which, unlike Chloride of 
Silver, are soluble in water, and may be washed off; thus, 
NaO.SA + AgCl = AgCS.O^ -f NaCl. The Hyposul- 



SULPHUR. 



173 



Fig. 143. 



phites of Silver, Gold, and Platinum have not succeeded 
well as electro-plating baths for deposition of their respec- 
tive metals. 

Compound with Hydrogen. 

Hydrosulplmric Acid — HS. Sulphuretted Hydrogen. 
Sp. Gr. 1.17. 

Prepai^ation. — By reaction of diluted Sulphuric acid on 
Sulphide of Iron, FeS -f H0,S03= 
reO,S03 + HS, or of Hydrochloric, 
acid on Tersulphide of Antimony, 
SbSs + 3HC1 = SbCl + 3HS. The 
Sulphide of Iron may be placed in a 
flask like Fig. 143, and dilute acid 
introduced by the tube, as required 
to evolve the gas. Emitted from or- 
ganic matters containing Sulphur, 
from drains, sinks, etc. It is this 
gas which blackens spoons employed 
in eating eggs, by forming on their 
surface black Sulphide of Silver, 
AgS. 

Properties. — A colorless gas, smell- 
ing like rotten eggs ; liquefied under 
17 atmospheres; poisonous; burns 
with a pale-blue flame, forming water 
and Sulphurous acid ; instantly decomposed by chlorine, 
owing to its superior affinity for Hydrogen. 

Test. — A black precipitate with Acetate of Lead, 
PbO,C4H303 + HS = HCCJIaOa + PbS. 

Uses. — Since it precipitates many of the metals from 
their acid solutions, by forming with them differently col- 
ored Sulphides, insoluble in water or acids, it is incessantly 
used in the laboratory to recognize the various metals, and 
separate them from each other. Sulphur baths, or those 
15* 




174 SELENIUM— PHOSPHORUS. 

containiug sulphuretted hydrogen dissolved in water, are 
prescribed for cutaneous diseases. 



Sym. Se. SELENIUM. Eq. 39.28. 

Discovered by Berzelius, 1817. Sp. Gr. 4.5. 

Sources. — Found combined with certain metallic sul- 
phides ; very rarely as Selenides. Obtained by a compli- 
cated treatment of a red deposit formed in the works at 
Fahlun, where sulphuric acid is made from pyrites con- 
taining Selenium. 

Properties. — As thus obtained Selenium is a reddish- 
brown, semimetallic-looking, amorphous solid; sp. gr. 4.3. ; 
fuses at 220°, and evolves when heated a disgusting smell. 
It resembles sulphur very closely, existing in three corre- 
sponding modifications: 1st, amorphous, which has just 
been described ; 2d, vitreous ; 3d, as crystallized from 
solution in Bisulphide of carbon, rhomboidal prisms. Its 
compounds with Hydrogen and Oxygen are analogous to 
those which sulphur forms with the same elements, viz., 
Hydroselenic acid, HSe; Selenous acid, SeOa; and Se- 
lenic Acid, SeOs; and, like sulphur, it combines directly 
with Chlorine and Iodine. 



Sym. P. PHOSPHORUS. Eq. 32. 

Named from 1"^?, light; and t-^p^?, carrying. First 
obtained by Brandt, of Hamburg, in 1660. Found as a 
phosphate of lime in many rocks. By their decom- 
position phosphate of lime passes into the soil, from 
thence into many plants, and finally into the bones of 
animals, forming their chi«f earthy constituent; phos- 
phorus seems essential to the brain and nerve tissue, and 
is an ingredient of albumen and fibrin. 

Preparation. — When bones are burned, they are con- 
verted into a tribasic phosphate of lime, SCaOjPOj. 'if 



PHOSPHORUS. 175 

this be treated with Sulphuric acid, Superphosphate 
of lime is formed; thus, 3CaO,P06 + 2(HO,S03) = 
2HO,CaO,P05 + 2(CaO,S03). The acid solution is 
filtered from the insoluble sulphate of lime, evaporated to 
a syrup, and then heated to redness, with one-fourth itis 
weight of charcoal. The superphosphate of lime is first 
decomposed into bone-ash and tribasic phosphoric acid, 
3(2HO,CaO,P05)=3CaO,P05-f 2(3HO,P05) ; afterwards 
the hydrated phosphoric acid so formed is deoxidized by 
the charcoal, 2(3HO,P05) + 16C=2P4-6H + 16CO. 

Properties. — A semi-transparent, colorless, wax-like 
solid, which emits white alliaceous fumes in the air. Has 
a sp. gr. 1.83; melts at 111°; boils at 550°; easily 
ignited; very poisonous ; its vapors produce necrosis of 
the jaw-bone, and horrible suffering to workmen engaged 
in its manufacture; exists in five forms. 1st. 1'he Trans- 
parent, just described. 2d. White ; formed by exposing 
the first to light under water, which renders it opaque, 
and less fusible. 3d. Black, by suddenly cooling melted 
phosphorus. 4th. Viscous; suddenly cooling phosphorus, 
heated to near its boiling-point. 5th. Red, by keeping 
phosphorus for 48 hours, at a temperature of about 480°. 
This variety does not fume, is hard to ignite, not poison- 
ous ; melts at 482°, and may be restored to the ti-ans- 
parent condition by heating to 500° out of contact with 
air. Phosphorus cannot be cryslallizcd by fusion, but 
from its solution in essential oils, sulphide of phospho- 
rus, and sulphide of carbon, it deposits rhomboidiri dode- 
cahedrons, and burns under hot water in a jet of Oxygen. 

Test. — Gives green color to hydrogen flame. 

Use. — For friction matches. 

Compounds with Oxygen. 
1st. Oxide of Phosphorus — P^O. Formed in small quanti- 
' ty,when P. is burned under water in oxygen; a yellow powder 



176 PHOSPHORDa. 

2d. Hypophospliorous Acid— PO. Syrupy liquid. 

3d. Piospliorous Acid — PO3. A white deliquescent, 
iDflammable powder. 

4th. Phosphoric Acid. — PO5. This is formed as a 
snowy powder, when phosphorus burns in oxygen. 

Use. — Its intense avidity for water makes it one of the 
best desiccating, or drying agents, known to chemists. 

Hydrates of Phosphoric Acid. — Besides this anhydride 
of phosphoric acid, three diflferent hydrates of phosphoric 
acid are known : 

1st. Protohydrate, or Metaphosphoric acid, H0,P05. 

2d. Deutohydrate, or Pyrophosphoric acid, 2 H0,P05 

3d. Tritohydrate, or Tribasic Phosphoric acid, 3HO,P05. 

They are remarkable for forming with bases, three 
entirely diflferent classes of salts, containing, respectively, 
one, two, and three, equivalents of water, or a base. 

Compounds with Hydrogen. 
They are three in number ; viz. PjH, PH2, and PH3. 
The first is solid ; the second liquid ; and the third is a 
gas, at ordinary temperatures ; the last is the most im- 
portant, and is known as 

Phosphuretted Hydrogen Gras. — It is prepared by heat- 
ing Phosphorus with concentrated solution of caustic 
potassa, in a flask, carefully filled with these materials ; 
Hypophosphite of Potassa is formed at the same time ; 
4 P + 6 HO + 3 (KO,HO) == 3 (KCPH.O^) + PH3 . 

Properties. — When the gas so obtained 
is allowed to escape into the air through 
the waters of the pneumatic trough, each 
bubble, as it breaks, takes fire sponta- 
neously, and produces a snowy white 
wreath of phosphoric acid, which curls in- 
r ward as it ascends. 

Or, if fragments of Phosphide of iJalcium 




METALS. lit 

are thrown into a glass of water, mutual decomposition 
will ensue, the oxygen of the w*ier going to the calcium, 
and the phosphorus and hydrogen uniting, and escaping 
in bubbles, which ignite as they reach the air. (See Fig. 
144.) 

Combination with Iodine. — Phosphorus combines with 
Iodine so readily that these two bodies will unite in the 
solid form, at ordinary temperatures, with great vigor. 
Thus, if we throw a few flakes of Iodine upon a bit of 
Phosphorus, they will, at once, combine igniting the 
latter. 



METALS. 
Properties of the Metals. 

The metals are mostly characterized by a peculiar 
brilliancy, termed the metallic lustre. This is lost, how- 
ever, when they are finely powdered, but may be restored 
by friction with a hard body. 

When in the massive state, they are opaque, but if 
reduced to leaves of excessive thinness, they transmit 
light; gold foil, for example, if not more than -^ouVuo ^^^^ 
thick, appears green when held between a bright light 
and the eye. 

Color. — Silver, platinum, tin, cadmium, and palhidium, 
are almost white ; lead and zinc are blue ; iron and 
arsenic, grey ; calcium and barium, pale yellow ; gold, 
bright yellow ; and copper, red. 

Smell and Taste. — Iron, tin, copper, and lead, when 
rubbed by the hand, emit a disagreeable smell, peculiar 
to themselves ; when arsenic is volatilized, it evolves a 
powerful odor of garlic. Some metals, as iron, and tin, 
have a nauseating metallic taste. 

Hardness, Brittleness, and Tenacity. — The hardnr^s of 



nS METALS. 

the metals is very variable : while potassium may be 
moulded like wax, and lead may be dented by the finger- 
nail, steel may be rendered hard enough to scratch glass 
like the diamond. 

So with regard to their brittleness and tenacity. Some, 
like antimony, arsenic, and bismuth, may easily be 
crushed to powder; while others, as gold and silver, 
resist very great pressure. An iron wire, an inch thick, 
will support, without breaking, twice as much as one of 
platinum having the same diameter, three times that of 
silver, five times more than gold, and twenty times as 
much as tin. 

Malleability and Ductility. — The order of malleability , 
by which is meant the property possessed by metals of 
being rolled or hammered into leaves, is as follows : — 

1. Gold; 2. Silver; 3. Copper; 4. Tin; 5. Platinum; 
6. Lead; T. Zinc; 8. Iron. 

If the metals were arranged according to their ductility, 
or the ease with which they are drawn into wire, the order 
would be : — 

1. Gold; 2. Silver; 3. Platinum; 4. Iron; 5. Copper; 
6. Zinc; 7. Tin; 8. Lead. 

Their Specific Gravity varies from that of Lithium, 
0.593, to that of Platinum, 21.5 ; their Fusibility, from 
— 39°, the freezing-point of mercury, to 3844°, the fusing- 
point of forged iron, and even far beyond this, to where 
platinum melts in the oxyhydrogen flame. 

Chemical Properties of the Metals. 

Action of Oxygen and of Water on the Metals. — Potas- 
sium and Sodium combine with Oxygen, and decompose 
water at the ordinary temperature ; Iron, Lead, etc., only 
when highly heated; and Gold, Platinum, Iridium, etc., 
cannot be directly combined with Oxygen, or be made to 
decompose water at any temperature. 



METALS. 1Y9 

Classification of the Metals. — The metals are therefore 
arranged in six groups : — 

1. Metals of the Alkalies: Potassium, Sodium, Li- 
fhium, and Ammonium. 

2. Metals of the Alkaline Earths: Barium, Stron- 
tium, Calcium, and Magnesium. 

Termed alkaline because they have a caustic action 
upon animal matters, and earths because their oxides are 
insoluble in water. 

3. Metals of the Earths : Aluminum, Glucinum, Zir- 
conium., Thorinum, Yttrium, Erbium, Terbium, Cerium, 
Lanthanum, Didymium. 

4. Metals, whose Oxides form powerful Bases : Man- 
ganese, Iron, Chromium, Nickel, Cobalt, Copper, Zinc, 
Cadmium, Bismuth, Lead, Uranium. 

5. Metals, whose Oxides form iceak Bases, or Acids : 
Vanadium, Tungsten, Molybdenum, Tantalum, Niobium, 
Titanium, Tin, Antimony, Arsenic, Tellurium. 

6. Noble Metals. — Gold, Mercury, Silver, Platinum, 
Palladium, Iridium, Osmium, Ruthenium, Rhodium. 

Salts. 

Definitions. — A salt is a body formed by the combination 
of an acid with a base. 

When an oxacid is united with an oxygen base it is 
termed an oxysalt : KO4-CO2 =K0,C02, Carbonate of 
Potash. 

The union of a Sulphur acid with a Sulphur base gives 
rise to a sulphosalt : KS+CS2=KS,CS2, Sulphocarbonate 
of Potash. 

When a hydracid unites with a base it forms water and 
a binary compound, termed a haloid salt: KO +I1C1 = 
KCl + HO; NaO-fHI=H04-Nar; CaO + nF=CaF + 
HO; n,0 + nCy=HO + H,Cy. 

A Neutral Salt is one which contains as many equiva- 



180 METALS. 

lents of acid as there are equivalents of Oxygen in the 
base, as CaO,C02, Carbonate of Lime; Pd02,2S03, Sul- 
phate of Binoxide of Palladium; AliOsjSSOa, Sulphate of 
Alumina. 

When a neutral salt reddens blue litmus paper it is 
termea a neutral salt with an acid reaction, as Nitrate of 
Copper, CuO,N05. 

If it turns red litmus-paper blue it is known as a neu- 
tral salt with a basic reaction, as Carbonate of Potash, 
K0,C02. 

An Acid Salt is one which contains more equivalents 
of acid than there are equivalents of Oxygen in the base, 
as Bichromate of Potash, KO,2Cr03. 

Note. — Salts are also termed monobasic, bibasic^ and 
tribasic, accordiag as they are formed by the union of a 
base with a monobasic, bibasic, or tribasic acid. 

A Monobasic Acid is one which combines with but one 
equivalent of a base, as Sulphuric, Nitric, etc. 

A Bibasic Acid neutralizes two equivalents of the base, 
as the Fyro2:>hosphoric, Tartaric, Racemic, and Gallic 
acids. 

A Tribasic Acid combines with three equivalents of the 
base, as the Tannic, Phosphoric, Citric acids, etc. 

A Basic or Sub-salt is one which contains fewer equiva- 
lents of acid than there are equivalents of Oxygen in 
the base, as Sub-Sulphate of the Sesquioxide of iron 
(Fe,03,S03). 

A Double Salt is one formed by the combination of two 
salts. The electro-negative body is usually the same in 
both salts, as KO,SO,+Al203,3S03+24HO, Alum, or 
the double Sulphate of Potash and Alumina; KCl-f- 
PtCla, double Chloride of Potassium and Platinum. 



\ 



POTASSIUM. 181 

GROUP I. 

Sym. K POTASSIUM. Eq. 39. 

Isolated by Davy, in 1807, from moistened Hydrate of 
potasBa placed in contact with the poles of a very power- 
ful galvanic battery. 

Preparation. — When Carbonate of Potassa and charcoal 
are intimately mixed together and subjected to intense 
heat, carbonic oxide and potassium vapor are set free. 
The latter is solidified by cold, and collected in a proper 
receiver, KO,C02+2C = K-{-3CO. 

Properties. — A bluish-white metal, which is brittle and 
crystalline at 32°, soft at 60°, liquid at 130°. Its specific 
gravity being only 0.865, Potassium will float upon water. 
Enters directly into combination with the halogens, and 
with Sulphur, Selenium and Tellurium, burning vividly 
when heated with them. So strong is its affinity for oxy- 
gen that it cannot be preserved in the open air, but only 
in a vacuum, or under the surface of some liquid, like 
Naphtha, which does not contain oxygen. When a lump 
of Potassium is thrown upon water, it unites with the 
Oxygen of that compound, forming potash, and setting free 
the Hydrogen. The heat developed in this action is so 
great as to render the Potassium red hot, and to ignite 
the liberated Hydrogen, which burns with a flame tinged 
purple by the vapor of the Potassium, which also burns. 

Compounds with Oxygen. 
Teroxide of Potassium — KO3. Formed when potas- 
sium is heated in an excess of dry oxygen gas. 

Potassa — KO. Generated by the oxidation of potassium 
in dry air. Known in chemistry as a rongont only in the 
form of Hydrate of Potassa, K0,H0. 

Sources. — Found combined with Silica in Mica and Fel- 
16 



182 POTASSIUM. 

spar. Bj decomposition of these two minerals, it passes 
into the soil. The fertility of land depends in great mea- 
sure upon the . quantity of Potassa which it contains. 
From the earth it is taken up by plants, and it is from the 
ashes of burnt trees that the carbonate of potash, or pearl- 
ash of commerce, is obtained. 

Preparation. — This hydrate is manufactured by dissolv- 
ing Carbonate of Potassa in 10 or 12 times its weight of 
water, and adding to the boiling solution a quantity of 
caustic lime, equal in weight to half the Carbonate of 
Potassa used, KO,CO,+ CaO,nO=KO,HO-f CaCCO^. 

Uses. — The glass maker unites it with sand to make 
Silicate of Potassa, one of the components of glass ; the 
soap-maker unites it with a fatty acid to form soft soap : 
the chemist absorbs carbonic acid with it, and decomposes 
by it all those metallic salts, the bases of which are insol- 
uble in water. It is very alkaline, and unctuous to the 
touch ; it instantly alters, and finally destroys the skin, 
for which reason it is employed as an escharotic, under 
the name of caustic potash. Ignited with the insoluble 
silicates, it renders them soluble in acids : this operation 
must be performed in silver capsules. 

Compounds with the Halogens. 

CMoride of Potassinm, KCl, is extracted from kelp, the 
ashes of burnt sea-weeds. It is used in large quantities, as 
a source of potassa in alum manufacture. The slaty clay 
which is used for making alum is filled with bisulphide of 
iron, FeSa', hence, on roasting and exposing to air and 
moisture, sulphate of the protoxide of iron and sulphate of 
alumina are formed. But alum is a double sulphate of |30- 
tassa and alumina. Chloride of potassium is therefore em- 
ployed to decompose the sulphate of iron : FeO,S03-}- AI2O3, 
3s63+KCl-fAq=(KO,S03-fAlA,3S03+24HO)-fFeCl. 

Also, to eflPect the decomposition of nitrate of limo in 



POTASSIUM. 183 

one mode of manufacturing saltpetre: CaO,N05+ KCi= 
K0,N05+CaCl. 

Iodide of Potassium, KI, is procured by digesting 2 
parts of iodine and 1 of iron in 10 parts of water; the pro- 
tiodide of iron so formed is afterwards converted into 
iodide of potassium by carbonate of potassa: Fe + I= 
Fel and Fel-f KO,C02=KI+reO,C02. 

Uses. — In the manufacture of the metallic iodides ; to 
dissolve the Iodide of Silver employed in iodizing photo- 
graphic paper, and as a remedy for glandular swellings. 

Compounds with Acids. Potassa Salts. 

Carbonate of Potassa — K0,C02. In commerce called 
Vegetable Alkali, Salt of Tartar, Dulcified Alkali, Pearl- 
ash, or simply Potash. 

Preparation. — Potassa, KO, exists in large quantities 
in plants, combined with various organic acids, such as 
Malic, Acetic, Oxalic, Tartaric, etc. These salts are all 
converted, by burning, into Carbonate of Potassa, and the 
latter may therefore be obtained by making a lye of wood- 
ashes, and evaporating until the carbonate of potassa 
crystallizes out. Birch-ash yields the purest potash, pine 
ashes the least; herbaceous plants furnish more than 
shrubs, and shrubs more than timber; the quantity 
afforded by the leaves is to that procured from heartwood 
as 25 to 1. 

Uses. — In the manufacture of soft soaps, crystal glass, 
Prussian blue, and sometimes to decompose the nitrates 
of lime and magnesia, employed in making saltpetre. 
When changed to the bicarbonate ov sal aeratus ^KO.CO., 
-f HO.COa), by passing a current of Carbonic acid through 
a solution of the carbonate, it is used in the treatment of 
gout and the like, and mixed with citric or tartaric acid, to 
make effervescing draughts. 

Sulphate of Potassa, K0,S03, obtained by neutralizing 



184 POTASSIUM. 

the Bisulphate of Potassa (KO,S03+HO,S03), which is 
left as a residue in the manufacture of Nitric acid with 
KOjCOa, is used as a gentle laxative. In analysis, the 
former salt serves to detect and separate baryta and 
strontia ; the latter as a flux for salts, or metallic oxides, 
which are required to be acted upon by an acid at a high 
temperature. 

Nitrate of Potassa — K0,N05. Salt of Nitre, Nitre, 
Saltpetre. 

Source. — Formed abundantly in the hot weather suc- 
ceeding rain-storms, in certain soils of Spain, Egypt, Per- 
sia, and the East Indies, which are rich in potash. (See 
Ammonia.) Incrusts the interiors of many caverns in the 
West, and in Ceylon. Artificially prepared by the oxida- 
tion of ammonia in the presence of a powerful base in 
nitre plantations ; animal refuse of all kinds, the cleaning 
of sinks, stables, etc., are thrown together with old mor- 
tar, plaster from ceilings, etc., into great heaps. After 
three years these nitre beds are w^ashed, and yield to 
every cubic foot 4 or 5 ounces of nitre. 

This salt crystallizes in the form 
Fig. 145. Q^ ^^ hexagonal prism. A slice of 

this, cut perpendicular to its axis, 
viewed between two polarizing 
bodies, as in Fig. 54, or 55, shows 
the system of colored rings and dark 
brushes, indicated in Fig. 60, when 
the plane of its two optical axes co- 
incides with the plane of the polar- 
izer, and the system represented in 
Fig. 145, when these planes are 
slightly inclined. 

Uses. Nitre is extremely valuable on account of the 

facility with which it yields up its oxygen. It is con- 
stantly employed to oxidize the metallic sulphides into 




POTASSIUM. 185 

sulphates, carbon into carbonic acid, etc. Ex. Rapid com- 
bustion {deflagration) of a mixture of carbon and nitre, or 
of sulphide of antimony (SbSg), or sulphur with nitre, when 
touched by an incandescent body. This property of nitre 
gives it wonderful adaptation for its use in 

Gunpowder. — Gunpowder, used in France, Prussia, and 
the United States in war, consists of 75 parts of saltpetre, 
12 i parts of charcoal, and 12? parts of sulphur. The salt- 
petre starts the detonation by giving up all its Oxygen to 
the Carbon to form Carbonic oxide and Carbonic acid 
gases, the Potassium and Nitrogen being thus set free. 
The former straightway seizes upon the Sulphur to form 
vaporous Bisulphide of Potassium, the latter flies off 
as gas : K0,N05 + S^ -f 4C = KS^ + 2C0 + 2CO2 + N. 
The temperature at the moment of explosion rises to 
2200°, high enough to melt gold and copper coin ; and 
dilates the liberated gases, already occupying an enor- 
mous volume, until an amount of powder which filled 1 
cubic foot of the gun, after firing, expands to 2000 cubic 
feet. 

Besides this important use of nitre in gun powder, 
butchers employ it to preserve meats ; physicians as a 
medicine. Lucifer matches are made with it. 

Chlorate of Potash — K0,C105. Largely manufactured 
by passing Chlorine through a thin cream of 1 part of 
Chloride of Potassium and 2 parts of Hydrate of Lime 
dissolved in water : KCl -f 6CaO + 6C1 = KO.CIO, + 
6CaCl. Ex. Kubbed with charcoal, sulphur, and phos- 
phorus the mixture explodes, in consequence of the rapid 
oxidation of these bodies by the Chlorate. 

XJi>es. — By the chemist and calico-printer as an oxidizing 

agent; in lucifer matches ; and in percussion powder for 

gun-caps. The friction tubes for cannon-firing are charged 

with a mixture of 2 parts of Chlorate of Potash, 2 of Sul- 

16* 



186 SODIUM. 

phide of Antimony, and 1 of powdered glass. A mixture 
of. Chlorate of Potash, dried Ferrocyanide of Potassium 
and Sugar has been used for blasting, under the name of 
white gunpowder ; but the ease with which it explodes by 
friction has rendered its manufacture dangerous. 

Test. — When a strong solution of Bichloride of Plati- 
num, is poured into a concentrated solution of a potash 
salt, a yellow double Chloride of Potassium and Platinum 
(KCl + PtCy precipitates. 



Sym. Na. SODIUM. Eq. 23. 

Discovered by Davy in 180Y, and obtained by him in the 
same manner as Potassium. Prepared like Potassium for 
commercial uses. 

Properties. — A bluish-white metal ; soft at common tem- 
peratures, melts at 194^. Decomposes cold water with 
the evolution of heat but not of light. The Oxide, Sul- 
phides, and Haloids of Sodium correspond in properties 
and mode of formation with those of Potassium. Sp. Gr. 
0.9T2. 

Chloride of Sodium — NaCl. Sea Mineral, or Rock Salt. 

Sources. — Found in Poland, England, Spain, and other 
places as a rocky deposit, often of great thickness and 
extent. Obtained likewise by evaporating in salt-pans the 
waters of the ocean, and those pumped from the salt-wells 
of Western Virginia and Pennsylvania. 

Uses. — To season food ; in the manufacture of Sulphate 
and Carbonate of Soda, of Hydrochloric acid, the bleach- 
ing Chlorides, and Chlorine; in forming salt-glaze upon 
pottery ; in manufacturing soap ; in preserving meat. 

Sulphate of Soda, NaO,S03, is manufactured on a vast 
scale in Leblanc's process for making Carbonate of Soda, 
by causing Sulphuric acid to react upon common salt; 
thus, NaCl-f HO,SOs=NaO,S03+HCl. It was for- 
merlv also in favorite use as a saline cathartic, under the 



SODIUM. 181 

name of Glauher^s salt, but it has gradually been replaced 
by Sulphate and Citrate of Magnesia. 

Carbonate of Soda, ]SiaO,C02, is prepared by throwing 
into an elliptical reverberatory furnace 1000 lbs. of salt 
cake, or Anhydrous Sulphate of Soda, obtained by the 
above reaction, intimately mixed with 1000 lbs. of dry 
chalk, and 350 lbs. of crushed coal. The Sulphate of Soda 
is reduced by the coal to Sulphide of Sodium, NaO,S03 4- 
4C =NaS -|- 4C0 ; and this Sulphide effects a double de- 
composition of the Carbonate of Lime, to form Carbonate 
of Soda and Sulphide of Calcium, NaS + CaO,C02 = 
NaOjCOa + CaS. Fifteen hundred pounds of this crude 
artificial soda or black ash may be obtained from the pre- 
ceding charge. Crystallized from its solution, it is known 
in commerce as sal soda. 

Uses. — The soap-makers use vast quantities of black 
ash to make from it, by treatment with milk of lime, their 
caustic Soda, or Soda lye, employed in the manufacture 
of hard soap : NaO,CO, + CaO,HO = NaO,HO -f CaO, 
CO2. Used as a detergent by the calico-printer, and, 
under the name of washing soda, in the kitchen. It 
unites with the grease wherever present, and forms with 
it a kind of soap. In the laundry for softening hard 
waters, by forming with the soluble salts of Lime and 
Magnesia insoluble Carbonates. In the manufacture of 
glass. Treated with excess of Carbonic acid it is con- 
verted into Bicarbonate or Supercarhonate of Soda (NaO, 
CO2 -f H0,C02). It is mixed with Rochelle salt in the 
blue paper which is sold, along with a white envelo^^e 
enclosing Tartaric acid, by druggists, as Seidlitz powders. 

Phosphates of Soda. 
Phosphoric Acid forms with Soda several crystallizable 
salts, which differ from each other in the number of equiva- 
lents of Soda united with one equivalent of the acid, viz : 



188 SODIUM. 

(a) The Tribasic 'Phospliates of Soda, which are three 
in number: — 

1st. Neutral Tribasic Phosphate, or Subphosphate of 
Soda (3NaO,P05+24Aq). 

2nd. Rhombic Phosphate of Soda, (2NaO,HO,P05 + 
24Aq). From this salt all the other Phosphates of Soda 
are formed. It has been longest known, and is familiar 
under the name of Commercial Phosphate of Soda. 

3rd. Biphosphate of Soda, (2HO,NaO,P05 + 24Aq). 

Test. — These three tribasic phosphates give with Ni- 
trate of Silver a yellow precipitate. They always require 
three equivalents of the salt, with which they react : thus, 

3NaO,P05 ^ r3(NaO,N05) 

2NaO,HO,P05 [-j-.3(AgO,N05) = 3AgO,P05+ j 2(NaO,N05) + HO,N05) 
2HO,NaO,P05i (NaO,N05+2(HO,N05) 

(6) Pyrophosphate of Soda (2NaO,PO5+10Aq). 
Test. — Gives a dense white precipitate with Nitrate of 
Silver. Reacts with two equivalents of another salt : thus, 

2NaO,P05+2(AgO,N05)=2AgO,P05+2(NaO,N05). 

(c) Metaphosphate of Soda (NaCPOs). 

Test. — Gives a gelatinous white precipitate with Ni 
trate of Silver. Reacts with one equivalent of another 
salt: NaO,P05 + AgO,N05=AgO,P05+NaO,N05. 

Uses. — Phosphate of Soda (2NaO,HO,P05) precipitates 
all the alkaline earths and metallic oxides. After the 
oxides of the heavy metals have been separated, it serves 
in analysis as a test for the alkaline earths in general; 
and after the separation of Baryta, Strontia, and Lime it is 
used, in conjunction with Ammonia, to precipitate Mag- 
nesia, as the basic Phosphate of Magnesia and Ammonia 
(NH40,MgO,HO,P05). Combined with Ammonia as mi' 
crocosmic salt (NaO,NH40,HO,P05), it is frequently pre- 
ferred to Borax as a flux before the blowpipe, because with 
many substances it gives a more brilliantly colored bead. 



LITHIUM. 189 

Biborate of Soda— NaO,2BO3+10Aq. Borax. 

Sources. — For many years the crude Borax, or Tinea} 
of commerce, was obtained by evaporation of the waters 
of certain lakes in Thibet. Now manufactured from the 
Boracic acid present in the lagunes of Tuscany, by neu- 
tralizing it with Carbonate of Soda, and allowing the satU' 
rated solution to crystallize. 

Uses. — When two oxidizable metals, such as Copper and 
Iron, are to be soldered together, the brazier sprinkles their 
surfaces with Borax. This dissolves off the oxide, which 
would otherwise prevent their union, as fast as it is 
formed. The goldsmith also emploj's it, in both refining 
and soldering the precious metals. It enters into enamels 
to render them more fusible, and into the composition of 
easily melted glasses ; it is employed in fixing colors upon 
porcelain, and for the glazing of some potteries. The free 
Boracic acid, which is present in Borax, along with the 
Borate of Soda (commonly called Biborate of soda), has 
a strong affinity for metallic oxides at high temperatures. 
It consequently forms wi4h them and the Borate of Soda 
before the blowpipe double borates, which have diflferent 
colors, and which serve to detect the different metals; 
with Oxide of Chromium, emerald green; with Oxide of 
Cobalt, a deep blue ; with Oxide of Copper, a pale green: 
with Oxide of Tin, an opal; with Oxide of Manganese, a 
violet, etc. 



Syin.Li. LITHIUM. Eq.7. 

Isolated by Davy by means of the galvanic battery, and 
named from -ki^Ooi, a stone, because it is found chiefly in the 
minerals, lepidolite, spodumene, and pcfalife. 

Properties. — A white metal, fusible at 350°, and burn- 
ing with a brilliant white light. It is the lightest of 
metals. Sp. Gr. 0.5930. 



190 AMMONIUM. 

Tests. — A purplish red color in the blowpipe flame, and 
one intensely bright red band in the spectroscope. 



Sym. NH4, or Am. AMMONIUM (hypotlietical). Eq. 18. 

Ammoiliacal Amalgam. — Ammonium has never been 
isolated, but is thought to exist in combination with Mer- 
cury in the compound which is formed when a concen- 
trated solution of Sal Ammoniac is poured upon Sodium 
Amalgam. The latter increases in bulk to 10 times its 
original volume, and acquires a pasty consistence, but 
nevertheless preserves its metallic lustre. On applying 
heat, Hydrogen and Ammonia are rapidly given ofiT, and 
pure Mercury left behind. From the character of its salts, 
Ammonium is placed among the alkaline metals. 

Oxide of Ammonium — NH^O. Ammonia. When Ammo- 
nia, NH3, enters into combination with anhydrous Sulphu- 
ric acid, SO3, it forms, not the (jrdinary salt. Sulphate of 
Ammonia, but a sulphate of very different properties. It 
is only when the hydrated acid, H0,S03, is combined with 
Ammonia that the regular Sulphate of Ammonia is formed. 
Therefore the basic water of the acid must have united 
with the gaseous Ammonia to form a new base, and this 
new base is what we shall henceforth regard as Ammonia, 
NH,0: thus, NH3 + HO,S03=NH,0,S03. 

Chloride of Ammonium, Muriate of Ammonia, Sal am- 
moniac — NH^jCl. The foregoing theory is strengthened 
by the fact, that when dry Hydrochloric acid is mixed 
with dry Ammoniacal gas, a white solid is formed which 
is ordinary Sal Ammoniac, and that this Sal Ammoniac, if 
dissolved in water, gives with Nitrate of Silver the 'same 
curdy precipitate as is formed when any other chloride 
reacts with Nitrate of Silver; that is to say, Sal Ammo- 



AMMONIUM. 191 

niac is not Hydrochlorate of Ammonia, NH3HCI, but 
Chloride of Ammonium, NHiCl. 

Sources. — It derives its name from Ammon, the ancient 
appellation of Egypt, where it was originally manufac- 
tured by the dry distillation of camel manure. It was also 
termed Spirit of Hartshorn, because obtained from horn- 
shavings by heat. Now manufactured by neutralizing, 
with hydrochloric acid, ammoniacal liquor, or water laden 
with ammoniacal salts, tar, and gther impurities taken up 
in washing coal-gas. 

Uses. — Owing to its great solubility and the resulting 
depression of temperature, it is used in freezing mixtures; 
in the preparation of the sesquicarbonate of ammonia 
(2NH40,3C02), or smelling-salts of the shops. To re- 
move rust from metals, particularly copper; in dyeing; in 
preference to chloride of sodium and chloride of barium for 
salting photographic paper ; it is sprinkled over iron-filings 
previously mixed with one hundredth part of sulphur, to 
form a lute for cementing iron into stone. A mixture of 
the chlorides of silver and ammonium is sometimes em- 
ployed for silvering copper and brass without heat. 

Uses of other Ammoniacal Salts. 
Carbonate of Ammonia, NH40,C02, is preferred, in con- 
sequence of its volatility on heating, to the carbonate of 
soda for precipitating the metallic oxides and earths. It 
is principally employed to separate the alkaline earths from 
magnesia, and to separate also sulphide of arsenic, which 
•is soluble in it, from sulphide of antimony which is in- 
soluble. Molyhdate of Ammonia, ^'lI^O.MoO;,, when 
added in great excess to their acid salts, serves to detect 
the faintest trace of phosphoric and arsenic acids. Oxalate 
of Ammonia, NIl40,C.,03, is a most delicate test of 
lime, precipitating it as an oxalate, CaO.SOa + NH+O.CiOj 
^CaO,C.208 -|- NH40,S03. Hydrosulphatc of Ammonia, 



1 92 BAHIUM. 

NH^SjHS, is employed to detect many of the metals by 
precipitating them as differently colored sulphides, and is 
used like sulphide of potassium for bronzing electro-plated 
medals. 



' GROUP II. 
Metals of the Alkaline Earths. 
Sym. Ba. BARIUM. Eq. 68.5. 

History. — Obtained by Davy, in 1808, from moistened 
Hydrate of baryta in contact with mercury, when the 
latter was made the positive pole of a powerful galvanic 
battery. It may also be procured by passing potassium 
vapor over baryta heated to redness in an iron tube. De- 
rives its name from j3api3$, henvy, owing to the great weight 
of its compounds. 

Properties. — A white metal, fusible under a red heat. 
Decomposes water with rapid evolution of hydrogen. 

Baryta, BaO, exists as a sulphate, heavy spar, which 
often constitute the vein-stone or gangue in mines, and 
as a carbonate, witherite. Obtained by calcination of 
nitrate of baryta. When heated to redness in an atmos- 
phere of oxygen, it is converted into the binoxide which is 
interesting as the source of binoxide of hydrogen. 

Uses. — Hydrated baryta, BaO, HO, and also the Chlo- 
ride of barium, BaCl, and Nitrate of baryta, BaO,N05, 
are employed to precipitate Sulphuric acid by forming with 
it, even in very dilute solutions, an insoluble Sulphate of 
baryta, BaO,S03. Fifty grains of nitrate of baryta mixed 
with 150 of sulphur, 100 of chlorate of potassa, and 25 of 
lampblack, constitute the '' green-fir e,^^ oi \he pyrotechnist. 

As a carbonate, BaO,C02, it is emplo\''ed in the analy- 
sis of siliceous minerals, which are insoluble in acids, 
forming when fused with them a silicate of baryta, and a 
soluble carbonate of the mineral oxide to be determined. 



STRONTIUM. 193 

The sulphate (BaOjSOg) is the permanent white of water- 
color artists ; it is also employed to adulterate white lead. 
When mingled in excess with this latter pigment it forms 
Dutch white ; in equal amount, Hamburg, and in lesser 
quantity, Venice white. But it becomes, when ground 
with oil, translucent, and impairs the opacity of the lead 
paint. 

Character of the Salts. — Colorless and poisonous, the 
best antidote being Epsom salts. Give a white precipitate 
with sulphuric acid, which is insoluble in acids. 



Sym. Sr. STRONTIUM. Eq. 43.84. 

Discovered by Davy, at the same time and in the same 
way as Barium, which it closely resembles in properties. 
It is found native as a carbonate, strontianite, and as a 
sulphate, celestine ; from the former, which was first found 
at the mining village of Strontian, in Scotland, it derives 
its name. All the salts of strontia are distinguished by 
the crimson tinge which they impart to the blowpipe 
flame ; and " red-fire " is made by mixing 40 drachms of 
dry Nitrate of Strontia (SrCNOs), with 10 of Chlorate of 
Potassa, 13 of Sulphur, and 4 of Sulphide of Antimony. 



Sym. Ca. CALCIUM. Eq. 20. 

Isolated by Davy, in 1808, with the galvanic battery, 
from moist lime. 

Properties. — As obtained by the fusion of sodium with 
iodide of calcium (Cal -f Na = Ca -f- Nal), it is a light 
yellow metal, which is very malleable, and which slowly 
decomposes water at ordinary temperatures. It enters 
into combination with oxygen, chlorine, bromine, iodine, 
and sulphur, when heated with them ; the union being 
accompanied by vivid light. Sp. Gr. 1.578. 

Lime — CaO. Caustic, or Quicklime, is obtained by 
burning lime in kilns having the form of a cone, inverted 
17 



194 CALCIUM. 

and truncated. Four parts of coal and one of lime having 
been thrown in from above, the fire is lighted bv means 
of fagots and gradually spreads throughout the kiln. As 
fast as the carbonic acid has been driven off, the lime is 
removed bv openings at the base of the kiln, while fresh 
layers of carbonate of lime and coal are added at the top. 

Uses. — When the oxyhydrogen flame is turned upon 
cylinders of quicklime, it causes them to glow with the 
intense brilliancy known as the Drummond Light. Mixed 
with water, a hydrate of lime, which is commonly known 
as slaked lime (CaO,HO), is formed. The latter has the 
power of uniting with the carbonic acid which is present 
in the atmosphere, and forming with it a solid carbonate 
of lime. Hence its utility, when stiffened with sand, in 
mortars and cements. 

Lime is also employed to loosen hair from hides in tan- 
ning ; to purify coal-gas, by absorbing from it sulphuretted 
hydrogen and carbonic acid ; to set free the stearic acid 
used for candles, from the fatty base ; to defecate sugars, 
or to remove the acetic and lactic acids present in the raw 
syrup, by forming with them insoluble acetates and lac- 
tates. It acts as a manure, by decomposing the organic 
matter which is present in the soil, and making it soluble 
in water. One ounce of lime is soluble in about *rOO ounces 
of water ; and its solution, which is known as lime-water, 
is valuable as a test for carbonic acid, in consequence of 
the turbidity arising from the faintest trace of the latter. 

When a stream of chlorine is passed over masses of 
slaked lime, a mixture of Chloride of calcium and Hypo- 
chlorite of lime is formed, which is familiarly known as 
Chloride of lime or Bleaching-powder : 2CaO,HO -f 201 
= CaCl+CaO,C10. 

The Chloride of Calcium, CaCl, alluded to above, has an 
intense avidity for moisture; and it is therefore used in 
the drying or desiccation of gases. 




CALCIUM. 195 

Carbonate of Lime, CaO,Co2, in the amorphous condi- 
tion, constitutes the different varieties of limestone, oolite, 
chalk, alabaster, and lithographic stone. Crystallized in 
rhombohedra, it is distinguished as calcite and Iceland spar. 
Sections of this, as described on page 6t, 
show, with polarizing instruments, colored 2' 

rings and crosses, as represented in Fig. 
57, and Fig. 146 ; the first with the polar- 
izer and analizer '' crossed," the last with 
these parallel. In six-sided prisms, 
CaOjCOa occurs as aragonite ; in minute 
granular crystals, as marble in its endless 
forms. It enters largely into the bony structure of men 
and animals, and is the chief component of corals and of 
shells. It is soluble in water containing carbonic acid ; 
and when the latter is driven off by heat or in any other 
way, it is again deposited. In this manner are formed 
the incrustations on the sides of steam boilers, which so 
frequently lead to explosions; and the stalactites, which 
depend from the ceiling, and the stalagmites, that rise from 
the floor, of caverns in limestone districts. 

Sulphate of Lime — CaO,S03+2HO. Gypsum is es- 
pecially valuable as affording a powder known as Plaster 
of Paris, when its water of cystallization has been driven 
off by a heat not exceeding 500°. This plaster has the 
singular property of expanding, when made into a paste 
with water, and then, in the course of a few minutes, of 
setting, or changing to a solid mass. It is therefore largely 
employed for copying medals, busts, statues, for moulds 
in stereotyping, etc., and as cement, stucco, etc. 

Tribasic Phosphate of Lime, 3CaO,P05, forms more 
than half of the bones of men and other animals. When 
converted to the acid, or superphosphate of lime (CaO, 
2HO,P06), by heating with two-thirds its weight of sul- 
phuric acid, it is largely employed in the manufacture of 
phosphorus, and as a manure. 



196 



MAGNESIUM. 



Character of Lime Salts. — They are all colorless, and 
afford, with oxalate of ammonia, a copious precipitate of 
oxalate of lime, CaO,C203 + 2H0. 



Sym. Mg. MAGNESIUM. Eq. 12. 

Discovered by Bussy, in 1828. 

It is prepared by heating the anhydrous double Chloride 
of Magnesium and Sodium with metallic Sodium. The 
process for manufacturing on the large scale was patented 
and is carried on in England by Sonstadt ; in this country 
it is made under the same patent by the American Mag- 
nesium Company, Boston, Massachusetts. (See Journal 
of Franklin Institute, Vol. 51, p. 69. 

Sources. — Combined with carbonic acid, as a double 
carbonate of lime and magnesia, forming magnesian lime- 
stone, or dolomite. Exists in the waters of the ocean, as 
a chloride, and of many mineral springs, as a sulphate. 
Enters into the composition of many rocks and minerals. 
Properties. — Resembles silver in color and lustre, zinc 
in fusibility and volatility. Yery ductile, and malleable; 
crystallizes in octahedrons. Not acted upon by cold, 

oxidized by hot water. 
Burns in air producing 
a brilliant white light, 
capable of employ- 
ment for illuminating 
and photographic pur- 
poses. Sp. Gr. 1.7. 

In order to make its 
combustion regular in 
these cases, the mag- 
nesium, in the form of 
a narrow ribbon, is 
fed by clockwork, from 



Fig. 147. 




MAGNESIUM. 191 

a brass nozzle, A, beyond which it burns. This appara- 
tus, known as a Magnesium Lamp, is shown in Eig. 147. 
The clock-work is contained in B C, its motion is con- 
trolled by the fly-wheel, B, and it is wound up by the key, 
D. The mirror, E F, reflects, and concentrates the light, 
and the whole apparatus may rest on a table, or be held 
by the handle, G. This light has been used to photograph 
dark interiors, coal-mines, the Pyramids, etc., and to take 
photographic portraits, at night. This light is superior in 
amount to a good lime light, and approaches even the elec- 
tric light obtained from 50 Bunsen 7 inch cells. In actinic 
force it surpasses all other artificial lights. 

Oxide of Magnesium — MgO. Magnesia; Calcined Mag- 
nesia. Prepared by driving off the carbonic acid and 
water contained in magnesia alba by long continued 
heat ; a soft, bulky, white, tasteless, and nearly insoluble 
powder. 

Carbonate of Magnesia — MgOjCOa. Occurs in nature, 
in rhombohedral crystals — magnesite. Mixed with hydrate 
of magnesia, it forms the subcarbonate of magnesia, or 
magnesia alba of pharmacy, 4(MgO,C02 -f MgO,HO 4- 
6H0.) 

Sulphate of Magnesia— MgO, SO3+6HO. Epsom Salts. 
Formed by dissolving Magnesite in Sulphuric acid, and 
separating the sparingly soluble sulphate of lime by fil- 
tration ; thus, MgO.CO^ + nO,S03 = MgO.SOa -f HO + 
CO,. 

Phosphate of Magnesia and Ammonia— 2MgO,NII,0,POi 
4- 12H0. When it is desired to remove magnesia from 
solution, it may be done by adding some soluble phos- 
phate, together with ammonia; when an insoluble phos- 
phate of magnesia and ammonia is formed. 

Silicates of Magnesia. — Occumative as Talc, 2(MgO, 
SiOa) -f 2MgO,3Si03 ; Steatite or Soapstone, MgO,SiO, 
17* 



198' ALUMINUM. 

4-2MgO,3Si03; Meerschaum, 2MgO,3Si03 + 4Aq; Ser- 
pentine, 2(MgO,Si03) + MgO + 2Aq, and many others. 

Character of the Magnesian Salts. — Bitter to the taste. 
Many magnesian minerals have a silky lustre, and feel 
unctuous to the touch. 

Test. — A white precipitate, with Phosphate of ammo- 
nia. 



GROUP III. 

Metals of the Earths. 

Sym. Al. ALUMINUM. Eq. 13.7. 

First procured by Wohler, in 1827, by decomposing 
Chloride of Aluminum in a platinum tube, by means of 
Potassium, Al.Cls + 3 K = 3 KCl + 2 Al. 

Properties. — In color and hardness, aluminum closely 
resembles zinc. It may be rolled into very thin foil, and 
drawn out into fine wire. It conducts electricity almost 
with the rapidity of silver ; struck with a hard body, it 
gives a clear and musical ring. On account of its light- 
ness — being but 2^ times heavier than water — audits 
inalterability in air, many attempts have been made to 
employ aluminum as a substitute for silver, in articles of 
jewelry, and table use. Sp. Gr. 2.5. 

Sesquioxide of Alnmimiin, or Alumina— AI2O3. When 
this earth is found crystallized in oature, and of a dark 
red color, it is known as oriental ruby ; when blue, as 
sapphire; green, oriental emerald; if it is yellow, it is 
called oriental topaz; and if violet, oriental amethyst. 
To the dark-colored and dingy crystals the name of 
corundum is given, and to the granular masses, so 
valuable for polishing, the term emery is applied. 

It is obtained as a gelatinous hydrate, when carbo- 
nate of ammonia is added to the sulphate, or other 
salt of alumina : A1A,3 SO3 + 3 (NH40,C02) + Aq = 



ALUMINUM. 199 

SHO^Al^Os + 3(NH40,S03) + SCO^ + Aq. In this con- 
dition it dissolves readily in potash and acids, but if 
rendered anhydrous by ignition, it dissolves with diffi- 
culty. 

Uses. — Alumina has a strong attraction for water, of 
which it retains no less than 15 per cent. ; hence, the 
value of clay as an ingredient of the soil. 

It forms with most coloring-matters, insoluble com- 
pounds, called lakes. If the dyer were to soak his cali- 
coes in the dyestuff alone, the color would be removed 
from the cloth at the first washing. He first immerses 
them in a solution of some mordant like alumina, which 
has an attraction for both the cotton fibre and the color- 
ing material, strong enough to resist the action of water. 
To obtain the alumina for this purpose, alum (KOjSOg + 
Al203,3S03 + 24HO), which has been manufactured by 
the process described under Chloride of Potassium, page 
182, is decomposed by carbonate of soda ; the cotton 
fibre forms a strong mechanical combination with the 
alumina thus set free, by which it is enabled to hold the 
coloring- matter fast. 

Besides its above-mentioned use, alum is employed in 
the sizing of paper, the preparation of sheep-skins, and in 
clarifying sugars, etc. 

Silicates of Alumina. — When silicate of alumina 
(Al203,3S03) is combined with silicate of lime (CaO, 
SiOg), it produces a number of minerals, which have the 
remarkable property of boiling up, on being heated in the 
' blowpipe flame, and are therefore called zeolites, from 
Cfw, I boil. Combined with the silicates of potassa, soda, 
lithia, or lime, silicate of alumina forms fcJd^pai^ and 
feldspar, when mingled with quartz and mica, produces 
the well-known gneiss and granite rocks. The beautiful 
topaz is a silicate of alumina combined with fluoride of 
aluminum, AljFj; and the j^ohemiau ganiet, so highly 



200 GLASS. 

prized for its intense blood-red color, is a silicate of alu- 
mina colored by the sesquioxides of iron and chromium. 

Vses. — When the granite rocks crumble away beneath 
the slow but resistless action of storms and rain, they 
afford the different varieties of clay. The latter, when 
stained by sesquioxide of iron, is used as a pigment under 
the name of yellow and red ochre ; if free from stains of 
iron it is called pipe-clay, and is largely manufactured into 
tobacco pipes. A peculiar variety of clay is termed kaolin. 
It is of the highest importance, because it forms, by 
fusion with silicate of potassa and lime, porcelain and 
China. When the clay and other ingredients used in 
pottery are not so pure and fine, the various kinds of 
stoneware and earlhenware are formed. A porous clay, 
which has the property of drinking oil and grease into 
its capillary vessels, is extensively used for scouring 
woollens and cloths, under the name of fuller^ s earth. 



GLASS. 

When silica, obtained from quartz rock or pure white sand, 
is fused with alumina and the carbonates of potash and lime, 
a double silicate of potash and lime is formed, which is 
known under the name of Bohemian and crown-glass. 
The former can be submitted to intense heat without 
melting, and is therefore invaluable to the chemist in the 
combustion of organic bodies. The latter is combined 
with flint-glass to correct the chromatic aberration of 
lenses. 

If soda is used instead of potash, a double silicate of 
soda and lime is formed ; and this is familiar to us as 
French plate, and ordinary window-glass. The above 
silicates are mixed with clay and oxide of iron, w^hen it 
is unnecessary to preserve the transparency of the glass ; 
and in this manner wine-bottles, carboys, etc., are made. 



GLUCTNUM, ETC. 201 

Character of Alumina Salts. — They all have an alum- 
like taste ; turn blue litmus-paper red ; give an azure with 
nitrate of cobalt before the blovi^pipe, and a bulky gelatinous 
precipitate with ammonia. 



Sym. Gl. GLUCmUM. Eq. 26.5 

Discovered by Wohler. It derives its name from y^vxv?, 
sweet, in allusion to the remarkable taste of its salts. 
When combined with silica and alumina it forms the 
beautiful green beryl and emerald. 



Sym. Zr. ZIRCONIUM. Eq. 33.6. 

Isolated by Berzelius. It occurs in nature as a silicate, 
forming zircon and the bright red hyacinth. 



THORIUM (Th, 59.6), YTTRIUM (Y, 32.2), ERBIUM 
(Er, — ), TERBIUM (Tb, — ). 

Thorium is remarkable as occurring in the form of a 
protoxide, ThO, forming the earth, thoria. It was dis- 
covered by Berzelius, in 1829, in a rare, black mineral 
named thorite, which is found in Norway. 

Yttrium was found by Wohler, and Erbium and Ter^bium 
by Mosander, 1843, in a mineral called gadolinite, which 
occurs at Ytterby, in Sweden. 



CERIUM (Ce, 46.), LANTHANUM (Ln, 47), DIDY- 

MIUM (Dy, 48). 

The first of these rare metals was discovered by Klap- 

roth, and the other two by Mosander, 1839, in Ccritc. 

They are so little known that, until recent Iv, they wcie 

all confounded together, under the name of Cerium. 



202^ MANGANESE. 

Metals Lately Discovered by means of the Spectral 

Analysis. 

Sym. Rb. RUBIDIUM. Eq. 85. 

Bunsen and Kirchhofif, 1860. Both Rubidium and 
Caesium were originally found in the mother liquor of 
mineral waters ; particularly of the salt-springs at Durk- 
heimer. They have since been met with in a few minerals, 
as lepidolite. Rubidium produces in the spectroscope 
two bright red lines beyond Fraunhofer's line A ; and 
hence in a part of the spectrum usually invisible. (See 
plate facing page 123. Rb.) 



Sym. Cs. CESIUM. Eq. 133.03. 

Bunsen. Distinguished by two blue lines in the spec- 
trum ; which are of great intensity and sharpness of out- 
line. (See plate facing page 123. Ce). 



Syin.TI. THALLIUM. Eq. 204. 

Crookes. Found in Lipari sulphur and pyritous ores. 
Gives a green line in spectrum. (See plate, Tl.) 



Sym. In. INDIUM. Eq. 37.07, 

According to Reich and Richter; but 35.918 as given 
by a later authority. Found in Freiburg ores of arsenical 
pyrites, blende, and galena. Gives dark blue lines. 



GROUP lY. 
Metals whose Oxides form strong Bases. 
Sym. Mn. MANGANESE. Eq. 27.67. 

Discovered by Gahn, in 17Y4. Found principally in 
the state of black oxide, MnOa, as Pyrolusite. 

Preparation. — An artificial oxide is obtained by calcining 



MANGANESE. 203 

the carbonate in a well closed vessel. This is mixed with 
oil and ignited in a covered crucible, by which means the 
oil is converted into charcoal very intimately mixed with 
the oxide. The above process is repeated several times. 
The mixture is next made into a thick paste with oil and 
introduced into a crucible lined with charcoal, and filled 
in with charcoal-dust. This is then heated to redness, 
after which the cover is well luted down and the whole 
exposed for an hour and a half to the greatest heat of a 
wind furnace. The metal is found as a button at the 
bottom of the crucible. 

Properties. — Manganese is a greyish white metal like 
cast-iron ; oxidizes rapidly in the air ; in water it evolves 
hydrogen. Sp. Gr. 8.013, t.05, 6.850, and t.O, according 
to different authorities. 

Compounds with Oxygen. 

Protoxide — MnO. 

Forms the basis of the common salts of Mn. They 
are similar in form, or isomorphous, with those of mag- 
nesia and protoxide of zinc. They are neutral, and of a 
pale rose color. 

Sesquioxide— Mn203. 

Sources. — Braunite ; and, as a hydrate, manganite. 

Properties. — A feeble base, isomorphous with alumina 
and sesquioxide of iron. 

Binoxide— MnOa. 

Sources. — Pyrolusite, psilomelane. 

Uses. — When the materials employed in the manufac- 
ture of glass cantain prot-oxide of iron, this substance 
stains the glass green. To remove this stain, MnOj is 
added, which yields part of its oxygen to the iron, con- 
verting it into a sesquioxide, which has but little coloring 
effect, and being itself reduced to a sesquioxide, which is 
not a coloring body, although the deutoxide itself stains 



204 MANGANESE. 

ficlass of a beautifQl amethystine tint: it is this MnO, 
which colors the amethyst. 

Mixed with acids, afifords an excellent oxidizing agent ; 
ignited, gives off one-third of its oxygen, leaving the 
red oxide: — SMnOj = (MnO,Mn203) -f 20; heated with 
concentrated sulphuric acid, it yields half its oxygen : — 
MnO, 4- H0,S03 = MnO,S03 + HO + ; extensively 
employed in manufacturing chlorine: — Mn024-2B[Cl=Mn 
CI + 2H0 + CI. It is largely used in making bleaching 
powder, 18,000 tons being annually consumed in England 
for this purpose alone. 

Permanganic Acid— MujOt. 

When manganate of potassa or chameleon mineral, 
K0,Mn03, formed by heating equal weights of caustic 
potash and binoxide of manganese, is thrown into water, 
it first becomes green, then purple, and at last claret- 
colored ; and a permanganate of potash, KO,Mn207, is 
formed. 

Use. — As an oxidizing agent. If permanganate of 
potash be added to sulphuric or hydrochloric acid contain- 
ing sulphurous acid in solution, the sulphurous acid is 
oxidized to sulphuric by the permanganate of potash, 
while the latter at the same time loses its color; it may 
therefore be emplo3^ed to detect the sulphurous acid. 

Sulphate of Manganese— MnO.SOs+YHO. 

Preparation. — Formed by heating the binoxide in sul- 
phuric acid. 

Use. — When cloths moistened wnth this salt are passed 
through a solution of bleaching-powder, an insoluble hydrate 
of the binoxide is thrown down upon the woollen or cotton 
fibre, and dyes it a permanent brown. Water and air test. 

Character of the Salts of Manganese. — They have a 
pale rose color and an astringent taste. Before the blow- 
pipe they give, with borax, an amethystine bead in outer 
Qame ; with carbonate of soda, a bluish-green bead ; with 



IRON. 



206 



hydrosulphate of ammonia, a flesh-colored precipitate; 
Tith the alkalies and their carbonates, give a white. 



Sym. Fe. 



moN. 



Eq. 28. 



Fig. 148. 



Sources. — Free in stones of meteoric origin ; as an ore, 
everywhere abounds. 

Properties. — White color, perfect lustre, highly mallea- 
ble, ductile ; most tenacious of all metals ; oxidizes in damp 
air, and decomposes water at a red heat; strongly mag- 
netic. Sp. Gr. 7.8. 

Protoxide — FeO. 

Preparation. — Precipitates as a 
white, bulky hydrate, when an al- 
kali is added to any protosalt of 
iron. 

Properties. — Absorbs oxygen ra- 
pidly, and changes to sesquioxide. 
It is a powerful base, and forms salts 
isomorphous with magnesia and ox- 
ide of zinc ; which have a pale green 
color and an astringent taste. 

Sesquioxide— Fe203. 

Sources. — Anhydrous, the specu- 
lar iron ore and red hcematite ; as a hydrate, brown 
hcem.atite. 

Properties. — Forms with acids, reddish salts of an acid 
reaction and astringent taste ; with the more powerful 
Dases it displays the part of an acid. Combines, for 
example, with protoxide of iron to form black oxide, Fcg 
04= FeO,Fe203. The black oxide also exists in nature 
as the loadstone, forming a valuable ore of iron, and a 
source of magnetism. Fig. 148. Antidote for As. 
18 




206 IRON. 

Ferric Acid— FeOg. 

Preparation. — By oxidizing sesquioxide of iron with 
nitre, at a red heat. 

Properties. — Forms salts easily decomposed by organic 
matter ; and, with the exception of Ferrate of Baryta, 
very unstable. 

With chlorine, iodine, and bromine, iron forms proto 
and sesqui-salts. 

Sulphides of Iron. 

ProtosulpMde — FeS. 

Pre])aration. — Four parts of powdered sulphur are 
strongly heated with t parts of iron filings. 

Uses. — It is a black, brittle substance employed in the 
laboratory as a source of sulphuretted hydrogen. FeS + 
HO,S03=FeO,S034-HS. When 60 parts of iron filings, 
2 of sal ammoniac, and 1 of sulphur, all in powder, are 
made into a paste with water and applied immediately as 
a luting to iron vessels, it quickly sets as hard as iron 
itself, by the formation of a sulphide. 

Bisulphide— FeSj. 

Sources. — Exists as iron pyrites or fooVs gold ; and 
appears in many cases to be derived from the deoxidation 
of sulphate of iron by organic matter. Combined with 
the protosulphide, forms magnetic pyrites (2FeS,FeS2), 
and with arsenic, arsenical pyrites or mispickel (FeSajFe 
As). 

Use. — Under the name of mundic, iron pyrites is 
largely employed in the manufacture of sulphuric acid to 
afTord sulphurous acid by ignition in the open air. W^s- 
pickel is roasted to form arsenious acid, AsOg — the white 
arsenic of the shops. 

Carbides of Iron. 
White Cast-iron is a compound of 4 equivalents of iron ' 
with 1 of carbon, Fe^C. Malleable iron is cast-iron from 



CARBIDES OF IRON. 



20t 



which nearly all the silicon and more than four per cent, 
of carbon has been burnt out by being — 1st. Heated in 
contact with air — refining. 2nd. Heated with black oxide 
of iron — puddling. In this way but one-half per cent, of 
carbon is left in the purest bar-iron. Steel is malleable 
iron which has been heated to redness with charcoal fur 
about 48 hours — cementation. It contains from 1.8 to 2.3 
per cent, of carbon. 

By Bessemer's process, malleable iron and steel are 
made from pig-iron without the aid of fuel, by causing 
hot air to pass through the liquid iron. The carbon is 
burnt away with the formation of carbonic oxide, and 
develops in its combustion sufficient heat to continue the 
operation without the assistance of external fire. 

This process is conducted in a large iron vessel (Fig. 149) 

Fi<r. 149. 




called a " converter," capable in some cases of containing 
five tons of iron. Air is carried from condensing pumps 
into this vessel through the trunion A, whence it passes 
by a pipe, B, to the bottom, and so escapes into the melted 
iron within. 

When the operation is finished, the molten steel is 



IQt COMPOUNDS OF PROTOXIDE OF IRON. 

poured out (by turning the converter over with appropriate 
machinery) and run into moulds. The quality of this 
steel is much improved by mixing with it, after conversion, 
a small amount of iron containing manganese. 

In smelting, sulphides, nitrides, and phosphides of iron 
are formed in small quantities. They all have deleterious 
efTects ; sulphur rendering bar-iron red short, the others 
cold short. 

Compounds of Protoxide of Iron. 

Sulphate of Protoxide of Iron— FeO,S03+tAq. Cop- 
peras, Green Yitriol. 

Preparation. — Obtained by dissolving iron in dilute sul- 
phuric acid, or by roasting iron pyrites, and exposing to 
air and moisture. 

Properties. — Forms large green crystals, which slowly 
efSoresce and absorb oxygen in the open air; forming a 
subsulphate of the sesquioxide. Combines with the sul- 
phates of potassa and soda to form double sulphates 
isomorphous with those formed by the alkaline sulphates 
with sulphate of copper. (FeO,S03-f K0,S03-f 6Aq) and 
(CuO,S03-fNaO,S03H-6Aq). 

Uses. — As a reducing agent. It is, therefore, employed 
to precipitate gold and palladium from solution in the 
metallic state; and to develop photographs, by removing 
all the oxygen from the silver salt ; thus, 3 (AgOjNOa) + 
6(FeO,s63) ^ 2(FeA,3S03) -f FeA.SNOs + 3Ag. To 
form Nordhausen Sulphuric acid, it is first dried and then 
distilled at a red heat. The sesquioxide of iron which is left 
as a residue in this reaction, is sold as a polishing pow- 
der for glass and jewellers' ware, and as a red pigment, 
under the names of colcoihar, crocus of Mars, and rouge. 

Persulphate, or Sesquisulphate— Fe.Os.SSOs. 

Source. — Native in Chili, forming a white powder 
having the composition Fe^OajSSOa -f 9Aq. 

Properties. — Forms double salts with the alkalies, re- 



COBALT. 209 

sembling common alum in form, composition, and taste. 
E. g. NH.O.SOa + FeA, 3 SO, + 24 Aq. 

Note. — Salts of a metallic protoxide are frequently 
termed -ous salts, of a higher oxide -ic salts. 

A ferrous and a ferric nitrate (FeO,N05 + 6 Aq), and 
(Fe^OajSNOj) maybe formed, as well as a ferrous ace- 
tate, and a ferric oxalate ; but they are not important. 

Carbonate of Protoxide of Iron — FeO,C02. 

Sources. — The two valuable ores, spathic iron and clay 
iron-stone, and ferruginous springs. The excess of car- 
bonic acid in chalybeate springs holds the carbonate of 
iron in solution, and when the carbonic acid escapes, 
oxygen is absorbed from the air, and ochry hydrated 
sesquioxide of iron produced. 

Tests. — Ferrous salts, with ferrocyanide of potassium, 
precipitate Turnbull's blue, with ferricyanide Prussian blue. 

Ferric salts, with ferrocyanide of potassium, precipitate 
Prussian blue ; this freshly prepared dissolves in a solu- 
tion of oxalic acid, giving blue writing fluid. With sul- 
phocyanide of potassium give a blood-red precipitate; 
with tincture of nut-galls form ink. (See page 251.) 



Sym. Co. COBALT. Eq. 29.5. 

Discovered by Brandt, in It 33. 

Sources. — Tin-white cobalt, Co As, and cobalt glance, 
CoS„CoAs. 

Properties. — Reddish-gray color ; hard ; brittle ; almost 
as magnetic and infusible as iron. Slowly oxidizes in air. 
Not used in the metallic state, but in combination forms 
beautiful pigments. Sp. Gr. 8.5. 

It has three oxides ; the protoxide, CoO ; sesquioxide, 
C0.2O3; and cobaltic acid, C03O5. 

Uses. — Zaffre, used in enamel-painting, is an impure 
oxide of cobalt (made by roasting cobalt ore), mixed with 
18* 



^10 NICKEL. 

2 or 3 times its weight of sand. Smalt is a glass colored 
blue by oxide of cobalt. With alumina, oxide of cobalt 
forms cobalt-ultramarine, or Thenard^s blue ; with oxide 
of zinc, Binman^s green. 

CMoride of Cobalt — CoCl. 

Preparation. — Formed by dissolving the oxide in hy- 
drochloric acid, CoO + HCl = CoCl,HO. 

Uses. — When writing is executed in dilute chloride of 
cobalt, the rose-red marks made by the hydrated chloride 
are so faint as to be invisible, but when the water is 
driven off by heating the paper, distinct lines are visible 
of anhydrous chloride of cobalt, and of the blue-color 
characteristic of this salt in its anhydrous state ■ — sympa^ 
thetic ink. 

Tests. — With the alkalies, a blue precipitate ; with their 
carbonates, a pink. 

Sym. Ni. NICKEL. Eq. 29.6. 

First recognized as a distinct metal by Cronstedt, in 
1751. 

Sources. — Associated with cobalt, to which it bears a 
close likeness, in meteorites, and various ores ; extracted 
from kupfernickel, NiaAs, and arsenical nickel, NiAs. 

Properties. — A white, hard, malleable, ductile, very 
tenacious, difficultly fusible metal. Strongly magnetic 
at temperatures below 630°. Oxidized by air at high 
temperatures. Most nickel compounds have a green 
color. An alloy of 51 parts of copper, 30.6 of zinc, and 
18.4 of nickel, is highly prized for its malleability and sil- 
very lustre, and is well known under the name of German 
silver. Sp. Gr. 8.8. 

The Oxides of Nickel, NiO, and NigOs; its sulphides, 
NiS,Ni2S, and H^iS^] chloride, NiCl; sulphate (NiO,S03 
-I- T Aq), which forms with potassa and ammonia beauti- 



CHROMIUM. 211 

ful double salts (NiO,S03 + K0,S03 + 6 HO) and 
(NiO,S03 + NH40,S03 + 6 HO) ; and the various basic 
carbonates of nickel have at present no industrial ap- 
plication. 



Syiii.Cr. CHROMIUM. Eq. 26.7. 

Discovered by Yauquelin, in Vauquelinite, chromate 
of lead, in the year HOT. . 

Sources. — Chrome iron, FeOjCraOg. 

Properties. — A dark-grey metal, possessing a strong 
affinity for oxygen *, oxidizes in the open air below red 
heat, and deoxidizes nitric acid with violence. Sp. Gr. 
6.81. 

Uses. — Not employed in the metallic state, but as an 
oxide largely used in painting on porcelain, and in calico 
printing. 

Compounds with Oxygen. 

These are 5 in number, and agree in composition and 
properties with the corresponding ferric compounds ; the 
protoxide, CrO, is a powerful base, forming pale-blue 
salts ; the sesquioxide, Cr.^Og , is a feeble base, and forms 
poisonous green salts. It is not decomposed by heat, and 
is, therefore, used to color enamel green. CrO,Cr;i03 cor- 
responds to Magnetic Oxide of Iron ; CrOg, Chromic Acid, 
to Manganic and Ferric acids; CrgOy, to Permanganic acid. 

Chromic Acid — CrOg. 

Preparation. — 100 measures of saturated solution of 
bichromate of potassa are mixed with 150 measures of 
sulphuric acid, KO,2Cr03 + H0,S03 = K0,S03 + HO 
4- 2Cr03. 

PiKjperties. — As thus made, chromic acid forms bright 
red crystals, which are very deliquescent, and easily 



212 ZINC. 

decomposed into sesquioxide of chromium, by contact 
with organic matter. Hence its use as an oxidizing 
agent. It forms three classes of salts — basic, neutral, and 
acid. Of these the bichromate of potassa, KO,2Cr03, 
is most important ; it is used in dyeing, in the formation 
of aniline colors, and in photography. With logwood it 
makes a good ink ; 3 oz. of solid extract of logwood are 
dissolved in 3 gallons of hot water; to this is added ^ oz. 
of KO,2Cr03, dissolved also in a little hot water. The 
ink is then ready for use. The chromate of lead, PbO, 
CrOa, is the well-known chrome-yellow. Subchromate of 
lead, 2PbO,Cr03, which is formed by dipping the cloth 
moistened with chromate of lead into boiling milk of lime, 
2(PbO,Cr03) + CaO,HO = 2PbO,Cr03+ CaO,Cr03 + HO, 
is largely employed in dyeing. 

Tests. — With salts of lead, the chromates give a yellow 
precipitate ; with nitrate of silver, a red ; with subnitrate 
of mercury, an orange. 

Compounds with Chlorine. 

ProtocMoride, CrCl, valuable as a reducing agent, 
owing to its intense affinity for oxygen, and the Sesqui- 
chloride, Cy^CIs. 



Sym. Zn. ZINC. Eq. 32.6. 

Known in commerce since the time of Paracelsus, 1540. 

Source. — The chief ores of Zinc, or, as it is called in 
commerce, Spelter, are the Bed Oxide, ZnO, found at 
Pranklin, New Jersey; Blende, ZnS, found in Cornwall 
and Cumberland, England, in Saxony, and throughout 
Missouri, Wisconsin, Iowa, etc.; Smithsonite, ZnO,C02, 
worked in Silesia, Belgium, and England ; Calamine^ 
a hydrated Silicate of Zinc, found in Carinthia and near 
Bethlehem, Pennsylvania. 



ZINC. 213 

Extraction from Ores. — First powdered, then roasted, 
to drive off sulphur or carbonic acid, ZnS-f30=ZnO + 
SO^; ZnO,C02=ZnO + C02; and afterwards mixed with 
coke and distilled, ZnO + C=Zn+CO. 

Properties. — Hard, bluish-white metal; brittle at ordi- 
nary temperatures, malleable and ductile between 200° 
and 300^, very brittle at higher temperatures; fuses at 
773° ; boils at 1904°, its vapor burning brilliantly on ex- 
posure to air. In a moist atmosphere Zinc is soon coated 
with oxide, which prevents a deeper oxidation and fits it 
for many industrial uses. Moistened with water Zinc 
combines at ordinary temperatures with chlorine, bro- 
mine, and iodine. Sp. Gr. 6.8 to 7.1. 

Uses. — Metallic zinc is used for roofing, and as the oxida- 
ble metal in galvanic batteries. When sheet-iron is plunged 
into molten zinc and sal ammoniac the Oxide of Zinc is 
dissolved by the sal ammoniac as fast as formed, and the 
two metals are firmly united, forming galvanized iron. 
Brass is an alloy of 2 parts of copper and 1 of zinc. The 
Oxide of Zinc, ZnO, is sometimes substituted for white 
lead, under the name of Zinc White, but is not so opaque 
and dead-white ; it is substituted for red lead in optical 
glass ; in an impure state, as obtained from the flues of 
furnaces in which brass is melted, it is sold as tutty. 
Pure ZnO is prepared, as at Bethlehem, Pennsylvania, 
by roasting Zinc ores (such as the Silicate) in open fires 
and carefully collecting the white fumes passing off. 
Chloride of Zinc, ZnCl, when in solution, is employed as 
an antiseptic and as a preservative of wood. The double 
Chloride of Zinc and Ammonium (NH^Cl+ZnCl) is em- 
ployed to remove the oxide from Zinc, in the process of 
soldering. 

Sulphate of Zinc— ZnO,S03 f 7 Aq. White Yitriol is a 
powerful emetic ; employed largely in calico printing. 

Tests. — White precipitates with all the usual reagents. 



214 CADMIUM — COPPER. 



Sym. Cd. CADMIUM. Eq. 56. 

Discovered by Stromeyer, 181*1. 

Sources. — Accompanies the ores of zinc ; Greenockite, 
CdS. 

Froperties.—JIas a color and cry resembling tin ; very 
soft, malleable and ductile; fuses at 442°; boils at 1580^; 
burns with salmon-colored fumes. Sp. Gr. 8.6. 

Uses. — Forms very fusible alloys^ thus, 4 parts of Pb, T 
parts of Bi, 1.5 parts of Cd, and 2 parts of Sn form an 
alloy, fusing at 140° Fahr. Sulphide of Cadmium^ CdS, 
forms an excellent bright-yellow pigment ; the Iodide^ Cdl, 
is employed by photographers to iodize collodion. 

Test. — Yellow precipitate of Sulphide with Sulphuretted 
Hydrogen and Sulphide of Ammonium. 



Syin.CliL COPPER. Eq. 31.7. 

Sources. — Found with cubic crystallization or massive 
at Lake Superior and in Siberia. The Cornish mines 
afford Copper Pyrites, CuaS-fFegSs. From the Urals 
and from Australia come blue and green Carbonates, Azu- 
rite and 3Ialachite ; from Cuba red and black Oxides and 
Sulphides ; from Chili a Chloride, Atacamite. 

Properties. — Yellowish-red metal, hard, very malleable, 
ductile, and tenacious. Fuses at 1996°; one of the best 
conductors of heat and electricity ; burns in chlorine spon- 
taneously, when in leaf form, and in oxygen at a moderate 
temperature. Sp. Gr. 8.9. 

Uses. — In coinage, alone or alloyed with nickel ; sheath- 
ing of ships; in many pieces of mechanism; forms the 
negative element in Daniel's battery (,Fig. 150, described 
page 98); alloyed with zinc forms brass, and, with different 
proportions of tin, bronze, bell-metal, gun-metal, and spec- 



LEAD. 



215 



ulum-metal. The Suboxide of Copper, Cu,0, is used to 
stain glass a ruby 
color ; the Black Ox- Fig. 150. 

ide, CuO, communi- 
cates a green color to 
glass, and is used to 
oxidize organic bodies 
for purposes of analy- 
sis. Sulphate of Cop- 
per, Blue Vitriol (CuO, 
SOg-f-SAq), is used in 
calico printing and in 
the manufacture of 
cupreous pigments. 

Tests. — Green color 
in blowpipe flame ; 
pale blue precipitate 
with Ammonia, dis- 
solving with dark blue 
color in excess of the 
reagent ; red with Ferrocyanide of Potassium 




MlillllllllllllllllllllllllllillM ^^^^^^^^^^^^ 



Sym. Pb. LEAD. Eq. 103.7. 

Sources. — Metallic Lead is rarely found native; gene- 
rally occurs as Galena, PbS, w^hich is worked extensively 
in Cornwall and Cumberland, England, throughout Spain, 
in Missouri, Illinois, Iowa, and Wisconsin. It is also 
.found combined with Oxygen, Selenium, and Tellurium; 
with Arsenic and Antimony; with Carbonic, Phosphoric, 
Arsenic, Yanadic, Chromic, Antimonic, Molybdic, and 
Tungstic acids. 

Extraction from. Galena. — When Galena is roasted it ab- 
sorbs Oxygen, and part is converted into Oxide of Lead with 
evolution of Sulphurous acid, PbS-|-oO = PbO + SO,, part 
into Sulphate of Lead, PbS-}-40=PbO,SO,. When the 
Sulphide and Sulphate thus formed como in eontart witii 



216 LEAD. 

fresh Galena in the furnace, they are both decomposed, with 
the formation of metallic Lead and Sulphurous acid, 2PbO + 
PbS=3Pb+S02 and PbO,S03+PbS=2Pb + 2S02. 

Properties. — A soft, bluish-wliite metal, of small malle- 
ability, ductility, and tenacity ; fuses at 620°, and crystal- 
lizes in cubes on cooling. Sp. Gr. 11.36. The high me- 
tallic lustre of freshly-cut lead is speedily lost by the 
formation of a superficial film of oxide on exposure to air; 
but the formation of this oxide is due to the combined 
action of air and moisture, dry air alone or pure water 
alone having no power to oxidize lead. All natural 
waters hold in solution air, uncombined carbonic acid, 
various chlorides, nitrates, and ammonia, all of which 
favor the corrosion of lead. But they also contain sul- 
phates, phosphates, and carbonates, which generally coun- 
terbalance the action of the preceding substances ; and 
thus free water contained in leaden cisterns, or conveyed 
to inhabitants of towns, through leaden pipes, may not 
hold an injurious amount of the poisonous Oxide of Lead. 

Uses. — Metallic lead is but slightly affected even by 
boiling sulphuric acid, and is therefore employed in the 
sulphuric acid chambers. Since air and moisture only 
oxidize lead superficially, it is employed for cisterns, 
waters, gutters, roofing, etc. Lead, alloyed with about 
^ per cent of arsenic, to harden and granulate it, is the 
material of shot. When lead is alloyed with one-fourth 
its weight of Antimony it forms type-metal, which has the 
property of expanding on solidification, and thus copying 
a mould accurately. Pewter, Britannia metal, fusible 
metal, and the soft solder of tinsmitlis are alloys of lead. 
Of the four Oxides of Lead, Pb^O, PbO, PbO„ and 
PbaO^, the Protoxide, known as Litharge and Ma>sicot, is 
used to increase the siccative property of drying oils. 
Dissolved in lime-water, it is used as a hair-dye: the lime 
partially decomposes the hair, and the lead of the oxide. 



BISMUTH. 



21Y 



by combination with the sulphur of the hair, forms Sul- 
phide of Lead, which stains the hair a permanent black. 
When litharge is roasted, at a temperature of 600°, it ab- 
sorbs oxygen, and is converted into Minium, or Red Lead, 
PbaOj, which is principally employed in the manufacture 
of flint-glass. A combination of the Chloride and Oxide 
of Lead (PbCl,tPbO) is used as a pigment, under the 
name of Turner^ s yel- 
low. Its soluble salts Fig. 151. 
form most delicate tests 
for Sulphuretted Hy- 
drogen, which forms 
with them a black pre- 
cipitate. This may be 
illustrated in an amu- 
sing manner as fol- 
lows : We make a 
drawing on paper with 
a solution of Acetate 
or Nitrate of Lead, 
thickened so as to work 
well with a little gum. 
This drawing is of 
course invisible ; but 
if the paper is damp- 
ened by sponging on 
the wrong side, and 
exposed to HS, escaping from a tube, it is rapidly devel- 
oped. Such a design as Fig. 151 is one well suited to this 
sort of " spiritual photograph." 




Sym. Bi. 



BISMUTH. 



Eq. 208. 

Discovered by Agricola in 1529. 

Source. — Found native in quurtz-rock in Saxony, Tran- 



218 URANIUM, 

sylvania, and Bohemia, from which it is extracted by 
fusion in iron tubes, placed in an inclined position, so as 
to allow the metal to flow out from the lower end. 

Properties. — A hard, brittle, reddish-white metal, which 
fuses at 50T°, and crystallizes on slow cooling in very 
obtuse rhombohedra. Oxidized by air at high tempera- 
tures ; eagerly unites with Chlorine, Bromine, Iodine, and 
Sulphur. Sp. Gr. 9.t9. 

Uses. — The alloys of Bismuth with Tin and Lead melt 
easily, and on cooling expand greatly, for which reasons 
they are largely employed by die-sinkers, under the name 
of fvsible metal, consisting of 5 parts of Bi, 3 of Pb and 
2 of Sn. This will melt in boiling water. Some of its 
compounds are used as pigments, and the Subnitrate 
(SPbOg, 4NO5+9HO) as a cosmetic and in medicine. 

Test. — Yellow precipitate with Chromate of Potassa; 
soluble in Nitric acid. 



Sym. U. URANIUM. Eq. 60. 

Discovered by Klaproth, 1*789, in pitchblende (2U0, 
U2O3), which contains nearly 80 per cent, of the Black 
Oxide of Uranium. 

Properties. — Steel-white color; slightly malleable; 
burns brilliantly in air at high temperatures; dissolved 
by Hydrochloric and Sulphuric acids, with the formation 
of a Protochloride, UCl, and a Sulphate, U0,S03, which 
is employed in giving a Canary color to glass, and has the 
remarkable power of rendering it fluorescent. (See pages 
58 and 87.) 



TUNGSTEN — VANADIUM — MOLYBDENUM. 219 

GROUP Y. 

Metals whose Oxides are Weak Bases, or Acids. 

Sym. W. TUNGSTEN. Eq. 92. 

Discovered by D'Elhugart, 1181. 

Sources. — Found inwolf ram, Tungstate of Iron, and 
Manganese (MnO,W03,3reO,W03), and scheelite, Tung- 
state of Lime (CaO,W03). 

Properties. — A very hard, difficultly fusible metal, of an 
iron-gray color. Sp. Gr. 11.6. 

Uses. — Tungstic acid, WO3, is used in calico printing 
and as an anti-combustion mixture with starch, in the 
royal laundry of England. 

Test. — Treated with Hydrochloric acid and digested 
with Zinc, yields a blue color. 



Sym. V. VANADIUM. Eq. 68.46. 

Discovered by Sefstroem, 1830, in a Swedish iron ore 
from Taberg, but its principal ore is the Vanadate of Lead, 
found in Mexico and Chili. 

Properties. — Vanadic acid is reduced by Potassium in 
a covered porcelain crucible, V03-j-3K=3KO + V. 

Test. — When salts of Vanadic acid are mixed with tinc- 
ture of galls they form a very black ink, ineffaceable by 
acids, alkalies, and even by chlorine. 



Sym. Mo. MOLYBDENUM. Eq. 47.88. 

Discovered by Hj el m , lY 8 . 

Source. — Molybdenite, MoS^. 

Prepa7'ation. — The ore is first roasted, MoS.+ TOss: 
M0O34-2SO2, and the Molybdic acid so formed is made into 



220 TELLURIUM — ARSENIC. 

a paste with oil and charcoal, and exposed to a high heat 
in a crucible lined with charcoal, MoOs-f 3C=MoH-3CO. 

Properties. — White, brittle, and very difficult of fusion. 
Sp. Gr. from 8.615 to 8.636. Forms two basic oxides, 
MoO and M0O2, and a powerful metallic acid, M0O3. 

Test. — Purple precipitate with Terchloride of Gold. 



Sym. Te. TELLURIUM. Eq. 64.2. 

Discovered by Klaproth, 1795. 

Sources. — Found in Transylvania, rarely native, gene- 
rally as a Telluride of Gold, Silver, Bismuth, or Lead. 

Properties. — Sp. Gr. 6.65. Has the lustre of a metal, 
but so closely resembles sulphur and selenium that it is 
often classed among: metalloids. 



Sym. As. ARSENIC. Eq. 75. 

Source. — Generally occurs as an alloy with iron, cobalt, 
nickel, copper, or tin ; also as an Arsenate of the above 
metals, and, more rarely, in union with sulphur, forming 
realgar, AsSa, and orpiment, AsSg. 

Preparation. — When arsenical Sulphide of Iron, or 
mispickel (FeAs,FeS2), is roasted it undergoes oxidation, 
and its combined Arsenic is converted into Arsenious 
^cid, AsO.v The latter is conducted by the furnace-flues 
into large chambers, where it condenses as a white mealy 
powder. By heating this acid with pulverized charcoal in 
a Hessian crucible, upon the top of which a second cru- 
cible has been luted, the reduced metal is sublimed as a 
coating on the upper crucible. 

Properties. — In its chemical properties Arsenic is nearly 
allied to nitrogen and phosphorus, but, on account of its 
brilliant steel-gray lustre, its high specific gravity, and its 
facility in the conduction of electricity, it is here classed 



ARSENIC. 221 

among the metals. Heated to 35G°, it gives off an op- 
pressive garlicky vapor, which crystallizes on cooling in 
rhombohedra. Sp. Gr. 5.T to 5.9. 

Uses. — A small quantity of Arsenic is added to lead 
to produce a rounder shot. When partially oxidized by 
contact with moist air it is converted into fly-powder. 
Combined with Oxygen, as Arsenious acid, it forms sev- 
eral useful Arsenites. That of Potash has been long em- 
ployed in medicine under the name of Fowler''s solution. 
The Arsenite of Copper (2CuO,As03) is the delicate 
Scheele^s green. The double salt of Acetate and Arsenite 
of Copper — CuOjC^HaOs-f 3(CuO,As03) — is also used as 
pigment, and is known as Schweinfurt green. Arsenious 
acid (known in commerce as Arsenic or ratsbane) is more- 
over employed to prevent smut in grain, and as a soap for 
glass, by converting the Protoxide of Iron, which stains 
the glass green, into a harmless sesquioxide. 

Arsenic Acid, AsOs, prepared by oxidizing Arsenious 
acid with Nitric acid, has been employed as a substitute 
for tartaric and phosphoric acids in calico printing, but its 
use is attended with the same danger of poisoning to the 
workmen employed as there is in every other application 
of Arsenic and its compounds. 

The Bisulphide of Arsenic (realgar), AsSa, is an ingre- 
dient of the signal-light known as white Indian fire, and 
the Tersulphide (orpiment) is mixed with Arsenious acid 
to form King^s yellow. 

Tests. — Before the blowpipe evolves a peculiar odor of 
garlic; with ammonio-nitrate of silver, AsOj gives a yel- 
low precipitate, AsOa a dull red ; with ammonio-nitrate 
of copper AsOg gives a green precipitate. 

Detection of Arsenic. 
Marshes Test. — In a hydrogen generator, of the form in- 
dicated (Fig. 152), introduce some of the suspected sub- 
19* 



222 



TITANIUM — TIN. 



Fig. 152. 




stance. If Arsenic be pre ent, 
a glass or porcelain plate, held 
in the burning jet of hydrt gen, 
will be coated with a me ;allic 
mirror of Arsenic. 

Reinsch^s Test. — Boil the 
suspected liquid, acidified by 
one-tenth its bulk of Hydro- 
chloric acid, for half an hour 
with bright copper foil. The 
reduced Arsenic will be depos- 
ited as gray metallic crust of 
Arsenide of Copper. 



Sym. Ti TITANIUM. £^, 24.33. 

Discovered by Klaproth, 1795. 

Sources. — Ilmenite (FeOjTiOa) and rutile, hrookite and 
anatase, which are nearly pure Titanic acid, TiOg, occur 
ring under different crystalline forms. Copper-colored 
cubes, consisting of Cyanide and Nitride of Titanium are 
frequently found in iron slags. 

Uses. — The Oxide of Titanium is employed in painting 
porcelain and in coloring artificial teeth. 



SyTn.'Sii. 



TIN. 



Eq.58. 



Sources. — The only important ore is Tin-stone, SnOg. . 

Extraction. — After the ore has been roasted and washed 
it is mixed with one-fifth its weight of charcoal, and with 
a little lime, as a flux to the flinty gangue, and reduced by 
intense heat in a reverberatory furnace. 

Properties. — A very malleable, brilliant, white metal, 
which fuses at 442°. .Sp. Gr. 1.29. When a bar of Tin 
is bent it gives out a peculiar sound, called the cry of Tin. 



ANTIMONY. 223 

Burns brilliantly in air at high temperatures, forming the 
Binoxide, SnOj. 

Uses. — When molten Tin is poured upon the surface of 
sheet-iron or copper it forms a superficial coating of alloy, 
and the iron or copper so coated is extensively employed 
under the name of Tin-plate. The many alloys of Tin 
have previously been described under bismuth, copper, 
and zinc. An amalgam of Tin is employed for silvering 
mirrors. 

Neither the Protoxide, SnO, nor the Anhydrous Binoxide 
of Tin, SnOa, are employed in the arts; but when the 
Binoxide is combined with water it undergoes a remark- 
able change of properties, and forms two acids, Meta- 
stannic acid (SugOiclOHO), which is largely employed in 
whitening enamels, and, under the name of putty powder, 
for polishing plate, and Stannic acid (HO.SnOa), which 
forms in combination with soda, as Stannate of Soda 
(NaO,Sn024-4Aq), a much-used mordant. Of the three 
Sulphides of Tin, SnS,Sn2S3 and SnSj, the last is em- 
ployed, under the name of mosaic gold, in imitating 
bronze, and with electrical machines. 



Sym. Sb. ANTIMONY. Eq. 120.3. 

Discovered by Basil Valentine, at the end of the thir- 
teenth century. 

Sources. — Sometimes found native, frequently as an 
alloy with other metals ; but always extracted from the 
tersulphide of antimony — grey antimony ore SbSg. 

Propei^ties. — A brilliant, bluish -white, brittle metal, 
which fuses at 840^ Sp. Gr. 6.715. 

Usek. — The most important alloy of antimony is type- 
metal; which consists of 100 parts of lead and 20 of anti- 
mony and 5 of tin. For stereotyping, Pb 100, Sb IS, Sn 5. 

Compounds. — Antimony combines with both three and 



224 TANTALUM — COLUMBIUM MERCURY. 

five equivalents of oxygen, sulphur, and chlorine. When 
combined with potassa and tartaric acid, the teroxide, SbOg, 
forms tartar emetic (K0,Sb03,T} ; ground with linseed- 
oil, it is employed as a substitute for white lead. When 
an alloy of zinc and antimony is dissolved in dilute sul- 
phuric acid, the hydrogen set free from the water of the 
sulphuric acid unites, while in a nascent state, with anti- 
mony, to form antimoniuretted hydrogen. ZngSb+S^HO, 
S03)=3(ZnO,S03) + SbH3. 

Test. — The salts of antimony give an orange-red pre- 
cipitate of tersulphide, with sulphuretted hydrogen. 



Sym. Ta. TANTALUM. Eq. 68.72 

Discovered by Ekeberg, in yttrotantalite from Sweden, 
1802. 



Sym. Cb. COLUMBIUM. Eq. 68.8. 

Found by Hatchett, in a black mineral from Massachu- 
setts named columbite, in 1801. 



GROUP YI. 
Noble Metals reduced from their Oxides by Heat alone. 
Sym. Hg. MERCURY. Eq. 100. 

Sources. — Occasionally found in the metallic state, but 
generally combined with sulphur, forming cinnabar HgS. 
By heating, cinnabar gives off its sulphur as sulphurous 
acid, and its mercury as a vapor, which is collected in 
condensing chambers. 

Properties. — Mercury is the only metal which is fluid 
at ordinary temperatures. It freezes at — 39°, and boils at 
662®. Heated in the air to 650°, it is converted into the 
red oxide ; with chlorine, bromine, and many metals, it 



. SILVER. 225 

combines at ordinary temperatures; and also with sulphur 
and iodine, if triturated with them. Sp. Gr. 13.5. 

Uses. — Largely employed to form an amalgam with 
silver and gold, in order to extract them from their ores ; 
in the construction of thermometers, barometers, etc ; as a 
medicine ; as an amalgam wnth tin in silvering mirrors. 

Compounds. — Oxygen, sulphur, chlorine, bromine, and 
iodine unite with both one and two equivalents of mercury. 
Of the compounds so formed, HgS is known as the valu- 
able pigment vermilion ; HgaCl, Subchloride of Mercury, 
and HgCl, are known in medicine under the names of 
calomel and corrosive sublimate ; the Bromides and Iodides 
of mercury are employed in photography. 

Tests. — With iodide of potassium, a precipitate first 
yellow, then red ; silver-like deposit on copper foil. 



Sym. Ag. SILVER. - Eq. 108. 

Sources. — Found native, and as a chloride; but prin 
cipally obtained from its sulphide, AgS. The latter is fre- 
quently associated with lead to form argentiferous galena. 

Uses. — For coins and domestic utensils, and (as a coat- 
ing to less valuable metals) in plated ware. 

Photography. — A thin organic film, as of collodion, 
spread upon glass, and charged with iodide, bromide, and 
free nitrate of silver, suffers a change under the influence 
of light by which it acquires the power of reacting with 
certain solutions called developers, so as to produce an 
opaque insoluble body. By applying this property, nega- 
tive pictures are produced in the camera. Chloride of 
silver, in contact with organic matter, blackens by mere 
exposure to light, and to this fact we owe the production 
of positive pictures on paper from the negatives taken in 
the camera. 

Nitrate of silver thickened with gum Arabic and colored 
by India-ink is used for marking linen indelibly. The linen 



226 GOLD — PLATINUM. 

is first moistened with a solution of soda, which precipi- 
tates the oxide of silver upon the fibre of the goods. Un- 
der the name of Lunar caustic it is used as an escharotic. 
Test. — Hydrochloric acid or a soluble chloride, precip- 
itates a dense white cloud of chloride of silver, quickly 
changing to violet by exposure to the light. 



Sym. Au. GOLD. Eq. 197. 

Sources. — Found crystallized in cubes or octahedra, or 
in masses called nuggets. 

Properties. — Most malleable of metals; one of the best 
conductors of heat and electricity; fuses at 2016°. Un- 
afi'ected by any of the acids alone, but dissolved by a 
mixture of 1 part of nitric acid with 4 parts of hydro- 
chloric acid — aqua regia. Sp. Gr. 19.34. 

Uses. — In the state of pow^der, in painting porcelain, etc. 
Alloyed with copper, it is sufficiently hard for jewellers'- 
ware and coin. Employed to color glass a deep red. The 
cyanide of gold and potassium is used for electro-gilding. 

Test. — A mixture of protochloride and bichloride of tin 
precipitates from salts of gold the Purple of Cassius ; 
oxalic acid with heat a brown precipitate of metallic gold. 



Sym. Pt PLATINUM. Eq. 98.7. 

Sources. — Platinum, Palladium, Rhodium, Osmium, and 
Iridium are generally found associated together in the form 
of coarsely rounded grains. 

Properties. — Very lustrous, ductile, tenacious, white 
metal, fusible only by the voltaic battery or oxyhydrogen 
blowpipe. Sp. Gr. 21.5. 

Uses — Owing to its infusibility, and its power of resisting 
alkalies, and other chemical reagents, platinum is largely 
employed as the material of crucibles and stills Those 
intended for the concentration of sulphuric acid sometimes 
weigh upwards of 1000 ounces. By ignition of the double 
rhloride of platinum and ammonium, metallic platinum 



PALLADIUM. 



22T 



Fig. 153 



may be obtained in a very finely divided state, known as 
platinum sponge. This substance has a very strong ad- 
hesion for gases ; and it will condense a mixture of them 
to such an extent as to cause a chemical combination. 
Thus, if a jet of hydrogen is directed upon a piece of this 
substance in the air, the union 
of the H with from the air, 
will be so energetic as first to 
heat the Platinum sponge red- 
hot, and then ignite the hy- 
drogen jet. This action is 
applied to the useful purpose 
of procuring a light rapidly, 
in Dobereiner's lamp (Fig. 
153). The jet of hydrogen, 
when turned on, heats the pla- 
tinum sponge in the little box, 
f, is itself ignited, and so serves 
to light a taper, or the like. 

Even massive platinum 
possesses a like power. Thus 
a wire of this metal coiled over the wick of a spirit-lamp, 
as in Fig. 154, will continue to glow by causing a slow 
combustion of the alcoholic vapor after the flame has 
been extinguished. This is called the " flameless lamp." 

Fig. 154. 

Sym. Pd. PALLADIUM. Eq. 53.3. 

■ Discovered by Wollaston, 1803. 

Sources. — Forms from one-third to one 
per cent, of platinum ores. 

Properties. — A hard, ductile, white 
metal, very difficult effusion. Sp. Gr. 11.4. 

Ihes. — For graduated scales, and as 
Sliver, it is employed by dentists. 





228 . ORGANIC CHEMISTRY. 

Sym. It. IRIDIUM. Eq. 99. 

Descatils and Tenant, 1804. Sp. Gr. 21.15. 

Properties. — Very brittle, hard, white metal, fusible 
only by the oxyhydrogen blowpipe, and voltaic current. 
It is the heaviest of elements. Alloyed with osmium, as 
iridosmine, it is used for pointing pens. Its salts assume, 
when in solution, beautiful colors, from which property, 
the name iridium (from Iris, the rainbow) is derived. 



Sym. Os. OSMIUM. Eq. 99.6. 

Tenant, 1803. Sp. Gr. 21.4. 

Properties. — A white, very brittle metal. It forms no 
less than five compounds with oxygen, and four with 
chlorine. 



Sym. Rn. RUTHENIUM. Eq. 52.2. 

Klaws, 1845. Sp. Gr. 11.2. Most infusible of metals. 



Sym. Rh. RHODIUM. Eq. 52.2. 

Wollaston, 1804. Sp. Gr. 12.1. A white, very hard 
metal, scarcely fusible before the oxyhydrogen blowpipe. 



ORGANIC CHEMISTRY. 

Organic Chemistry treats of those organized bodies 
which have been formed under the influence of the vital 
force, and of the organic compounds which can be derived 
from organized bodies by the action of chemical reagents. 

Both classes of substances above referred to, are dis- 
tinguished from inorganic substances in several ways : 

1st. The mass of organic bodies consists of only six. out 



ORGANIC CHEMISTRY. 229 

of the sixty-four elements ; viz., carbon, hydrogen, oxygen, 
nitrogen, and, to a lesser extent, sulphur and phosphorus. 

2nd. But carbon, hydrogen, oxygen, and nitrogen, com- 
bine in so many, and such high proportions, that they 
alone, form a vastly greater number of bodies than is met 
with in inorganic chemistry. 

3rd. While inorganic compounds are formed by the 
pairing together of elements, or of binaries, or of ter- 
naries, with each other to form substances possessed of a 
certain symmetry of constitution, no such regularity is 
observable in organic chemistry. 

4th. Natural affinities seem often to be overruled by 
vital force, and organic compounds are formed in oppo- 
sition to the ordinary laws of chemistry. 

5th. It thus happens that organized bodies are com- 
paratively unstable, and prone to decomposition after the 
vital force, which created them, has ceased to act. 

6th. One element may frequently be substituted for 
another, without altering the essential characteristics of 
an organic compound. 

The substances met with in organic chemistry are most 
conveniently treated of under the following heads : 

I. Saccharine and Amylaceous Bodies. — Mostly nu- 
tritious substances with feeble affinities. They are com- 
posed of 24 equivalents of carbon, united with different 
proportions of oxygen and hydrogen. From them are 
derived the Alcohols and Ethers. 

II. Ethyl, diethyl, etc. — Compound radicals resembling 
I in their chemical relations hydrogen and the metals. 

III. Vegetable Acids. 
ly. Vegetable Bases : 
(a) Those found in nature. 
(6) Those formed artificially. 
V. Oils: 
(a) Fixed Oils or Fats. 

20 



230 



STARCH. 



(b) Essential or Yolatile Oils. 

YI. Cyanogen — a compound radical which resembles 
chlorine in its relations — and its compounds. 
YII. Organic Coloring-Principles. 
YIII. Albuminous Bodies. 



I. SACCHARINE AND AMYLACEOUS BODIES. 

1. Starch — C24H20O20. 

Sources. — The grains, roots, and stems of plants. It 
occurs in small, rounded grains, which vary greatly in 
size and appearance. Those of the tous les mots are 
about 3j^^ of an inch in diameter; and those of wheat, 
jQ^Q^th. Each grain is inclosed in a thin envelope, which 
is unaffected by cold water, but ruptured by the expansion 
of the starchy matter, on applying heat. 

Figure 155 represents some starch grains of the potato, 
as seen under the microscope, by ordinary light. 



Fig. 155. 



Fig. 156. 



Fig. 157. 






Figure 156 shows the appearance of the same, when 
viewed by polarized light, as indicated in pages 65 and 
66, a black cross being here developed on each grain. 

Figure 15Y shows one of these grains, after it has been 
boiled, as viewed under a powerful microscope. 

Preparations. — In order to free the starch granules j 
from gluten and other substances contained in the seeds, j 



GUM — LIGNINE. 231 

the latter, after being mashed, are washed upoa a cloth 
sieve with water ; the gluten remains behind. 

Properties. — An insipid, white solid, insoluble in cold, 
but slightly soluble in boiling water. By exposure for a 
length of time to a temperature of 400°, by gentle heat- 
ing in acidulated water, or by the action of diastase — a 
nitrogenized body formed from the gluten of germinating 
seeds — starch undergoes a peculiar change, and the sub- 
stance so formed, and which is known under the name of 
Dextrine or British Gum, is capable of solution in cold 
water. It is employed in the manufacture of envelopes, 
for dressing chintzes, and other cotton goods, in the fast- 
ening of mordants, etc. 

Arrow-root, tapioca, and sago, are varieties of starch. 

Test. — Iodine forms a beautiful blue compound with 
starch, which is insoluble. 

2. Gum — C24H20O20. 

A term applied to a number of substances which exude 
from the bark of trees, and form glassy, tasteless, and 
Inodorous masses, generally of a globular form. Dis- 
solved in water, they form mucilage, which is used as a 
substitute for paste. Gum Arabic, Gum Senegal, and 
Gum Tragacanth, are the important varieties. 

By boiling with Sulphuric acid, Gum Arabic yields sugar 
— with nitric acid, mucic acid. 

3. Lignine — C24II20O20. 

Modifications. — Woody Fibre ; Cellulose. 

Sources. — Found under many modifications : some- 
times it can be used as food ; as the pulp of roots, 
esculent plants ; at others it is indigestible ; wood ; shells 
of nuts : it is light and porous in elder pith or cork ; soft 
and pliable in hemp and cotton fibre. Fig. 158 shows 
Lignine of wood, as seen under the microscope. 




;2 LIGNINE. 

Properties. — Tasteless, insoluble in water and alcohol, 
and incapable of nutrition. At low 
Fior. io8. temperatures, strong oil of vitriol con- 

verts it into dextrine, and finally into 
glucose. It is not colored by iodine. 

By the action of equal parts of the 
strongest nitric and sulphuric acids, it 
is changed into a very explosive body, 
gun-cotton, or pyroxyline. It has two 
modifications ; the one, explosive, is insoluble in a mix- 
ture of alcohol and ether; the other is readily soluble, 
negative cotton. The latter is largely employed in pre- 
paring photographic plates, and in surgery. This change 
is not well understood, but it is supposed that the ele- 
ments of Hyponitric acid are substituted for several equiv- 
alents of hydrogen ; thus, to form gun-cotton, C24H20O20+ 
4NO5=C24Hi6(NO4)4O20 + 4HO; to form negative cotton, 
C24H20O20+ 6N05= C24HH(NO,)e02o+ 6H0. 

By acting on starch, grape-sugar, mannite, gum, and 
dextrine, with nitric acid of specific gravity 1.5, they are 
converted into a transparent, colorless jelly, known as 
xyloidin. Paper so treated acquires the appearance of 
parchment, and great combustibility. 

When wood is kept in dry air or under water it under- 
goes no change, but exposed to air, in presence of moisture, 
it absorbs oxygen, and experiences a slow decay, ereraa- 
causis, with the evolution of carbonic acid and water. 
The fertility of the soil depends in great measure upon 
the presence of decaying vegetable matter — humus, geine, 
ulmine — and the constant liberation of carbonic acid and 
water. 

When vegetable matter, such as aquatic and herb.v 
ceous plants, decay in marshy soils, peat is first formed, 
and afterwards, by the heat developed during decompo- 
sition, and by pressure changed into lignite, and finally 



CREOSOTE — PARAFFINE. 233 

into coal. Bituminous substances, like naphtha, petroleum^ 
asphaltum, etc., have probably been formed from plants or 
marine animals by slow decay under water. 

When wood is subjected to destructive distillation it 
gives off illuminating gas and many other hydrocarbons, 
along with water, acetone, pyroligneous acids, creosote, pyr- 
oxylic spirit, tar, etc. 

Creosote — C28H16O4. A colorless, oily, transparent liquid, 
which boils at 391°. It has a burning taste and a smell 
like burned meat. It is highly antiseptic, and it is owing 
to the presence of Creosote in tar, smoke, and pyroligneous 
acid that these substances have preservative properties. 
Used both internally and externally in medicine. 

When tar is distilled, a light and heavy oil passes over 
and a hard residuum, pitch, remains. The principal con- 
stituent of the light oil is Eupione, CgHe., of the heavy 
oil, Paraffine, C20H21. 

Paraffine is a tasteless, inodorous, white solid. It is 
insoluble in water, but dissolves freely in ether and oils. 
In consequence of its perfect indifference to the strongest 
alkalies and acids, it has derived its name from the two 
Latin words parwm and affinis, "without connection." 

On distilling bituminous coal, illuminating gas (which 
consists mainly of light and heavy carburetted hydrogen), 
carbonic acid, sulphuretted hydrogen, salts of ammonia, 
etc., and a viscid, resinous liquid, called coal-tar, are 
formed. 

Coal-tar yields on distillation a very volatile, inflamma- 
ble oil, which has been largely employed in Germany, 
France, England, and in this country, before the discovery 
of petroleum, for illuminating purposes. It has likewise 
been used extensively as a solvent for caoutchouc, in the 
manufacture of water-proof goods. 

This coal-tar oil is found, by treatment with acids and 
20* 



234 SUGARS. 

alkalies, to contain three classes of bodies: 1st. Sub- 
stances having a basic reaction, picoline, aniline, and 
leucoline ; 2nd. Acids, of which the most important is 
carbolic acid, or phenol; and 3rd. Neutral Hydrocar- 
bons, some of which are liquid, as toluol, cymol, benzol, 
and others solid, as naphthalin and paranaphthalin. 

NapMhalin, C20H8, separates in colorless, crystalline 
plates from the oil which comes over last in the distilla- 
tion of coal. It melts at 176°, boils at 413°, and, heated 
to a still higher point, burns with a red, smoky flame. It 
has the same composition as paranaphthalin, from which 
it mainly differs in being freely soluble in alcohol. 

4. Sugars. 

There are several varieties of sugar, all of which are 
sweet to the taste, soluble in water, and convertible into 
alcohol by fermentation. The most important are : — 

1st. Cane-sugar— C24H2,022. 

Sources. — Chiefly obtained from the sugar-cane; also 
found in the sap of the sugar-maple, in the juices of the 
beet and other roots, and the stalks of Indian-corn. 

Preparation. — After its juices have been expressed from 
the plant, they are evaporated to a thick syrup, from which 
the sugar crystallizes on cooling. What remains is treacle, 
or molasses. 

Properties. — White, inodorous, very sweet, and soluble; 
by slow evaporation it may be made to crystallize in 
iprisms-^r ock-candy. It melts at 356°, and forms, on cool- 
ing, barley-sugSiT ; at a temperature of 420°, it gives up 
four atoms of water, and is converted into caramel, 

2nd. Grape-sugar— CgiHasOag. Glucose. 
Sources. — Grapes, many other sweet fruits, and the 
solid part of honey. 

Preparation. — The juice of grapes is first freed from 



FERMENTATION. 235 

acid by neutralizing it with chalk, then boiled down to a 
syrup, clarified, and crystallized. Also prepared by con- 
version of starch or lignine, page 232. 

Properties. — Not by any means as sweet or soluble as 
cane-sugar. 

Test. — Grape-sugar" instantly precipitates suboxide of 
copper, from a boiling solution of sulphate of copper con- 
taining potassa, while cane-sugar slowly affects it. 



FERMENTATION. 

This term is applied to a decomposition of an organic 
body, resulting from the decomposing force exerted by an- 
other organic substance, called o, ferment, which is itself 
in process of decomposition. The molecular movement 
that is taking place among the particles of the ferment 
appears to be communicated to the fermentable sub- 
stances with which it is in contact, and causes them to 
break up into their simpler constituents. 

There are many ferments: yeast {}Nh\c\\ is the frothy 
matter that forms on beer and other liquids in process of 
fermentation), blood, albumen, caseine, and juices of many 
plants, and other putrescent matters. They all contain 
nitrogen, and derive from it their peculiar proneness to 
decomposition. So likewise there are several kinds of fer- 
mentation, distinguished as the 

(a) Lactic. — When putrid cheese is mixed with water 
and sugar, the caseine contained in the former substance 
produces fermentation, and the sugar is converted into 
Lactic acid, CgHsOsjHO, carbonic acid, and water. 

(b) Butyric. — If this fermentation is allowed to proceed, 
the lactic acrd disappears and Butyric acid, (CyllvOa.HO) 
is found in its place ; thus, C,,H2s02s=4IIO + 811 -f 8002+ 
2(C«H,03,HO\ 

(c) Viscous. — So also, when the juice of beets is ex- 
posed to a temperature of 100° for some time^ in contact 



236 WINE-ALCOBTOL. 

with air, it is converted into lactic acid and a viscous mu- 
cilaginous substance resembling gum Arabic. 

(cZ) Vinous or Alcoholic. — Pure grape-sugar undergoes 
no change in or out of contact with air, but when mixed 
with jeast it is rapidly converted into water, carbonic 
acid, and alcohol, C4H50,HO ; thus, C24H28028=4HO + 
8C02-f4(C,H50,HO). 

Alcohols and their Derivatives. 

1. Wine-Alcohol. 

(a) Ether. Action of acid on alcohol. 

(6) Aldehyde, Acetal, Acetic Acid, and Acetone. Ac- 
tion of oxygen on alcohol. 

(c) Chloral, Mercaptan. Action of chlorine and sul- 
phur on alcohol. 

2. Methylic Alcohol ; Wood Spirit, 
(a) Wood-ether. 

(6) Formic Acid. 

3. Propylic, Butylic, and Amylic Alcohol; their bomo- 
logues and derivd,tives. 

1. Wine-Alcohol — C4H50,HO. The alcohol obtained 
by fermentation, as above described, is very dilute. By 
successive distillations, however, it may be rectified until 
it contains but 10 per cent, of water. To obtain absolute 
or pure alcohol, common alcohol must be thoroughly mixed 
with half its weight of quicklime, and the spirit distilled 
from the mixture by the heat of a water-bath. 

Properties. — Pure alcohol is a limpid, colorless liquid, 
of a penetrating smell and agreeable taste. Its specific 
gravity at 60° is 0.T94. It boils at 113°, giving off a vapor 
which is very inflammable, and burning with a pale, smoke- 
less, hot flame. It has never been frozen, but at a tem- 
perature of — 146° becomes thick and tenacious, like 
melted wax. In solvent powers, it is inferior to water 
only, and dissolves many substances totally insoluble in 



ETHER. 



237 



water, like the resins. Not only is a great number of 
vegetable bodies, like the alkaloids, essential oils, etc., 
soluble in alcohol, but also the mineral alkalies and many 
salts. The process of malting, brewing, and bread-making 
depend upon the formation of alcohol. 

(a) Ether— C4H5O. 

Preparation. — A mixture is made of 8 parts by weight 
of concentrated Sulphuric acid and 5 parts of Alcohol, of 
sp. gr. 0.834, and heated in flask A. When its temper- 

159. 




ature has risen to 300°, the heat is regulated so as 
constantly to maintain that temperature. Under these 
circumstances Alcohol and Sulphuric acid combine, and 
the Sulpho-vinic acid thus formed is afterwards decomposed 
into Sulphuric acid and Ether, C4H50,HO + 2(HO,S03)= 
(C4H50,2S03,HO) + HO) and (CJl50,2S03,nO)-f H0= 
C4H50-f 2(HO,S03). The Ether and water vapor eon- 
dense into the inner tube, around which cold water is 
kept flowing (in at d and out at g), and are collected in a 
vessel placed at its lower end. The process may be made 



238 ALDEHYDE — ACETAL — ACETIC ACID. 

continuous, if alcohol is supplied to A ; for the acid serves 
merely to break up the alcohol which is constantly flowing 
into the flask, and at the end of the operation remains 
behind, while the ether distills over into the condenser. 

Properties. — Owing to its mode of formation, commer- 
cial Ether thus obtained is termed Sulphuric Ether. It is 
a colorless, limpid liquid, of fragrant, intoxicating odor, 
and pungent taste. At 60° its density is 0.72 ; it boils at 
96°, and remains liquid under the severest cold. Ether 
dissolves phosphorus, a few salts, most oils and fats, and 
some other organic compounds. When exposed to air. 
Ether absorbs oxygen and is converted into Acetic acid, 
C4H303,HO. Transmitted through a red-hot tube, it is 
resolved into light and heavy Carburetted Hydrogen and 
Aldehyde, C4H30,HO. Its vapor, when inhaled with air, 
produces insensibility to pain. 

(&) Products of the Oxidation of Alcohol. 

Aldehyde is a thin, colorless fluid, of a suffocating, ethe- 
real odor; density 0.Y92 ; boiling point t2° ; and burns with 
a pale flame. It is soluble in water, alcohol, and ether; 
dissolves sulphur, phosphorus, and iodine, and has such 
an affinity for oxygen that it reduces many metallic salts. 

Acetal, C12H14O4, is a colorless liquid, formed by the 
slow action of moistened platinum black, upon the vapor 
of alcohol diffused through a bell-glass, to which air has 
free access. By prolonging the action of platinum black, 
Acetal absorbs still more oxygen, and is converted first 
into aldehyde, and finally into acetic acid. 

Acetic Acid, €411303,110, is manufactured in Germany 
by causing a mixture of dilute alcohol and yeast to flow 
over wood-shavings, which are exposed in a current of air 
in a cask pierced with holes. The best vinegar, however, 
is made by the natural souring of wine when exposed to 
the air, 04H5O,HO4-4O = C,H3O3,HO + 2HO. Pyrolig- 



ACETONE. 239 

neous acid, formed by distilling wood in close vessels, is 
a very impure acetic acid, which is extensively employed 
in calico printing. 

Properties. — When concentrated it is a colorless liquid, 
of a pleasant, penetrating odor, and extremely sour taste 
It boils at 240°, giving off inflammable vapor; cooled 
below 60°, it solidifies in large transparent crystals ; at 
60° its density is 1.06. It readily mixes with water, al- 
cohol, and ether, and dissolves camphor and several resins. 
All the Acetates are soluble. The most important are : — 

Acetate of Lead, PbCC^HgOa+SHO, Sugar of Lead 
is formed by dissolving Litharge in Acetic acid. It is a 
powerful poison. Employed in analysis, and externally 
in medicine. Besides this neutral salt, there are various 
basic Acetates, as 2PbO,3C4H303 and 3PbO,C4H3034-HO. 
The latter crystallizes in needles, from a solution of T parts 
of litharge and 10 parts of sugar of lead digested in 30 
parts of water. It is used in the proximate analysis of 
organic compounds and in pharmacy under the name of 
Goulard^s Extract of Lead. 

Acetate of Copper, CuO,C4H303+HO, Distilled Yerdi- 
gris is obtained in dark-green crystals from a filtered 
solution of verdigris in hot acetic acid. It is used as a 
pigment. Yerdigris is a mixture of subacetates, procured 
by covering copper plates with pyroligneous acid or the 
refuse of grapes in wine-making. 

Acetate of Alumina, Al203,3(C4H303), is obtained by de- 
composing a solution of Sugar of Lead by Alum. Used 
as a mordant. 

Chloracetic Acid, C4C]303,HO, is formed by exposing 
crystals of Acetic acid, placed under a bell-jar filled with 
chlorine, to the direct rays of the sun. Three atoms of 
Hydrogen are replaced by 3 atoms of Chlorine ; thus, 
C4H3O3,HO + 6Cl=C4Cl3O3,HO-|-8n01. It closely resem- 
bles acetic acid, and forms analogous chloracetates. 

Acetone, C3H3O, Pyroacetic Acid is an inflammable 



240 METHYLTC ALCOHOI* 

liquid obtained by destructive distillation of metallic ace- 
tates ; thus, 2(PbO,C,H303) = 2Pb04-2(C3H30) + 2C02. 

(c) Action of Chlorine and Sulphur on Alcohol. 

Chloral — C4HCL0^ . When dry chlorine is passed into 
absolute alcohol, aldehyde is first formed, and hydro- 
chloric acid. By continuing the process, still more 
hydrogen is replaced by chlorine, and at last chloral is 
formed; thus, C4H602+2C1=C4HA + 2HC1, and C^H^O^ 
+ 6Cl=C4HCl302-f3HCl. It is an oily liquid, of a 
peculiar odor, which brings tears to the eyes, specific 
gravity 1.5, and boils at 201°. Bromine is likewise 
absorbed by alcohol, to form bromal, C4HBr302, and both 
are decomposed by caustic alkalies, with the production 
of a formate of the base, and chloroform or bromoform ; 
thus, KO,HO + C4HCl302=KO,C2H03 + C2HCl3. 

In like manner by the action of chlorine on light hy- 
drochloric ether, C4II5CI, one atom of hydrogen after 
another may successively be replaced by chlorine, until 
finally in the fifth distinct compound thus formed, sesqui- 
chloride of carbon, C4CI6, no hydrogen remains. 

Mercaptan — C4H(jS2, is a limpid liquid obtained by 
replacing, not the hydrogen in alcohol, but oxygen, with 
its congener, sulphur. 

2. MethyHc Alcohol— C2H402=C2H30,HO. 

Preparation. — Wood-vinegar, obtained by the destruc- 
tive distillation of wood, redistilled and treated with CaO, 
HO, yields about 1 p. c. of this substance, which is also 
called pyroxylic spirit and wood naphtha. It boils at 152°, 
has a density of 0.*798, will burn feebly, is miscible with 
water, alcohol, and ether, and will dissolve most resins, as 
also negative gun-cotton, to form collodion. 

(a) Methylic Ether.— C2H3O. Prepared by heating the 
above with 4 parts of strong Sulphuric Acid. It is a gas. 
Density 1.617, (liquefied only by great pressure,) of which 
water w\\\ dissolve 33 vols. 



FORMIC ACID. 



241 



(b) When wood-spirit is exposed to the action of moist- 
ened platinum black, under a bell-jar, to which there 
is free access of air, oxygen is absorbed, and formic acid 
(so called from its occurrence in the bodies of red ants, 
formica rufa) is formed ; thus, C2H4O2 -f 40 = C2H2O4 + 
2H0. 

Formic Acid — CaH^O^, is a clear liquid of acid taste, 
pungent odor, density 1.24, and when dropped upon the 
skin quickly blisters it. It boils at 212°, producing an 
inflammable vapor, and freezes at 32°. The alkaline for- 
mates are used in the reduction of metallic oxides. 

3. It will be seen on inspection, that methylic-alcohol, 
C2H4O2, and wine-alcohol, C4II6O2; wood-ether, C2H3O, 
and sulphuric ether, C4II5O ; formic acid, C2H2O4, and 
acetic acid, C4H4O4, all differ from one another by C2H2. 
Now, bodies which vary by C2H2, or by a multiple of it, 
are termed homologous, and their number is very great. 
If we add C2H2 to the alcohols, ethers and acids pre- 
viously mentioned, we shall get long series of new alco- 
hols and acids, many of whose members are already 
known to us ; thus, 



Alcohols. 


Acids. 




Ethers. 


Methylic, C2H4O2. 


Formic, 


C2H2O4. 


Methylic, C2II3O. 


Vinic, C4H6O2. 


Acetic, 


C4H4O4. 


Common, 041150. 


Propylic, C6H8O2. 


Propionic, 


CelleOi. 


CgIItO. 


Butylic, C8H10O2. 


Butyric, 


CsIIsOi. 


Butylic, CsIIgO. 


Araylic, Cioni202- 


Valeric, 


C10II10O4. 


Amylic, CioHnO. 


C12HUO2. 


Capi-oic, 


Cl2Th204. 




C1JT16O2. 


GEnanthylic, 


CuIIuO^. 




Caprylic, CieHigOz. 


Caprylic, 


CielluiCi. 


Caprylic, CioTInO. 



Besides the wine-alcohol obtained in the fermentation 
of saccharine matters, various acrid volatile-oils, called 
fusel-oWs, are formed, which likewise yield on distillation 
alcoholic liquids. The fusel-oil obtained by fermenting 
the husk or marc of the grape, for example, yields propi/I- 
alcohol, C6Hs02, the fusel-oil of beot-root sugar produces 
21 



242 ETHYL — METHYL. 

hutyl ' alcohol, C8H10O2, and that of potato-brandy, amyl- 
alcohol, C10H12O2. 

As methyl-alcohol, and wine-alcohol, yield formic acid 
and acetic acid by oxidation, so also propyl, butyl, and 
amyl-alcohol, are converted by absorption of oxygen into 
propionic, butyric, and valeric acids ; thus, C^HgOa (wine- 
alcohol) + 40=2H04-C4HA (acetic acid), and CioHi.O^ 
(amyl-alcohol) + 40 = 2HO-fCioHio04 (valeric acid). 

By treatment with strong acids, the alcohols may be 
converted into ethers, as described on page 23T. 

As we pass ft-om the lower members of these homo- 
logous series, to those containing a larger number of equiva- 
lents, we observe a corresponding change of properties ; 
they constantly approach nearer the solid form, and their 
boiling points increase by a fixed quantity, in the series of 
acids about 35.88°. 

II. Ethyl, Methyl, etc. — Compound radicals, resembling 
in their chemical relations, hydrogen and the metals. 

Besides common Ether, C4H5O, a great many other 
bodies may be formed from alcohol, which possess the 
properties of ether, and are termed compound ethers, such 
as Hydrocliloric Ether, C4H5CI; Hydrobromic Ether, 
C4H5Br ; :Nritric Ether, C4H50,N05 ; Oxalic Ether, C4H5O, 
C2O3, etc, Now all these compounds agree in containing 
C4H5; and it appears as though C4II5 might be transferred 
from one compound to another without suffering decom- 
position, in the same manner as an elementary body like 
zinc or copper. To a body which, like C4H5, plays the 
part of an element, we give a distinct name, and speak 
of it as a simple body. C4II5, for example, is denominated 
Ethyl, and represented by the symbol Ae. 

Ethyl, like zinc, combines with the halogen bodies to 
form haloid salts, and with oxygen and sulphur to form 
oxides and sulphides. The oxides, in turn, combine with 
the different acids to form ordinarv salts : thus : — 



ETHYL. 'M3 

Ethyl (symbol Ae) C4H5 

Oxide of Ethyl, Ether ^4^rfi* 

Hydrate of Oxide of Ethyl, Alcohol C4H50,H0 

Chloride of Ethyl, Hydrochloric Ether C4H5CI 

Bromide of Ethyl, Hydrobromic Ether C^HgBr 

Iodide of Ethyl, Hydriodic Ether C4H5I 

Cyanide of Ethyl = C4H5Cy 

Nitrate of Oxide of Ethyl, Nitric Ether C4H50,N06 

Silicate of Oxide of Ethyl, Silicic Ether 3(C4H50),SiOs 

The theory stated above was proposed by Liebig, long 
before the compound radical C4H5 was ever known in the 
separate state. Afterwards it was isolated, as a colorless 
liquid, by Dr. Frankland, from Iodide of Ethyl, by expos- 
ing it to the action of finely-divided zinc, at a temperature 
of 330°. By reference to the above table of Ethyl com- 
pounds, it will be seen that ether, C4H5O, is an Oxide of 
Ethyl, and alcohol, C4H50,HO, is a Hydrate of the Oxide 
of Ethyl, and that they may be expressed by the formulaa 
AeO and AeO,HO. 

Ethyl may be made to enter into combination even with 
hydrogen and the metals, and a long series of related 
bodies may be formed, as — 

Hydride of Ethyl C4H5H=AeH 

Zinc-Ethyl C4H5Zn--^AeZn 

Stannethyl C4H5Sn=AeSn 

Bismethyl (C4H5)3Bi=Ae3Bi 

Plumbethyl (C4H6)3Pb2=Ac3rb2 

Stibethyl (C4H5)3Sb=Ae3Sb 

Arsenethyl, etc (C4H5)3Asz=rAe3As, etc. 

And these compounds may be made to combine witli the 
halogen bodies, or with oxygen and the acids, to form crys- 
tallizable salts, as, for example : — 

Stannethyl AeSn=C4lT5Sn 

Oxide of Stannethyl AeSnOr=C4lT5SnO 

Chloride of Stannethyl AeSnCl^^C^lTgSnCl 

Nitrate of Stannethyl, etc AcSnO,N05=rC4H5SnO,N05. etc. 



244 METHYL. 

Methyl. — In like manner, in all the Methyl-Ethers it will 
be seen that CaH^ enters, and is displaced from combination, 
as a whole. This compound radical (C2H3) has not yet 
been isolated, but it has been confidenth^ assumed to exist. 
It is known as Methyl, and represented by the symbol 
Me. Wood-ether is regarded as an Oxide, and wood-spirit 
as a Hydrated Oxide of Methyl; thus: — 

Methyl CgHg^Me 

Oxide of Methyl, Wood-Ether CsHgO^^MeO 

Hydrate of Oxide of Methyl, AYood-Spirit.... CJl30,HO=MeO,HO 

Sulphate of Oxide of Methyl, etc C2H30,S03. etc. 

Chloride of Methyl C2H3CI 

Iodide of Methyl, etc CgHgT, etc. 

Hydride of Methyl CgHgH 

Zinc-Methyl, etc CJIgZn, etc. 

Kakodyl C4H6As=3(C2H3l2A3 

Kakodyl deserves especial mention. It is a compound 
radical, capable of entering into a large number of combi- 
nations, and of being displaced from them in the same 
manner as a metal. Its most important compounds are — 

Kakodyl (symhol Kd) C4H6AS 

Oxide of Kakodyl KdO 

Chloride of Kakodyl KdCl 

Terchloride of Kakodyl KdClg 

Kakodylic Acid KdOg 

Kakodylate of Silver AgO,KdOg 



Tersulphide of Kakodyl KdS 



Oxide of Kakodyl — KdO. Cadet's Fuming Liquid, 
Alkarsin. 

Preparation. — When equal weights of Acetate of Po- 
tassa and Arsenious acid are heated together, the acetone 
liberated by the decomposition of the Acetate of Potassa 
reacts upon the Arsenious acid to form Oxide of Kakodyl 
and Carbonic acid, 2(KO,C4H303)=2KO + 2C02+2C3H36, 




KAKODYL — PROPYL — BUTYL — AMYL. 245 

and 2C3H3O + As03= C4H6ASO + 2CO2. This process may 

be conducted in an eartiien retort placed in a furnace, and 

having its beak connected with a U shaped tube (Fig. 

160) plunged in a vessel filled with broken 

ice. In this U tube the Oxide of Kako- ^'^- ^^^' 

dyl will collect with some water which 

covers it. 

Properties. — A colorless, highly refrac- 
tive liquid; density 1.462, and boiling point 
802°. It is highly poisonous, and attacks 
the eyes and lining membrane of the nose. 
It takes fire in air, producing water, car- 
bonic and arsenious acids. When treated with corrosive 
sublimate and hydrochloric acid it yields an extremely 
poisonous liquid. Chloride of Kakodyl. 

Kakodyl— Kd. 

Preparation. — Digested with zinc the Chloride of Kak- 
odyl "suffers decomposition, with the formation of Chloride 
of Zinc and Kakodyl itself, KdCl-fZn=ZnCl + Kd. 

Properties. — A colorless, transparent liquid, of great 
inflammability. It boils at 338°, and at 21° crystallizes 
in transparent square prisms. Combines directly with 
oxygen, sulphur, chlorine, etc. Its teroxide, alkargen, 
KdOa, is a very stable acid, capable of uniting with me- 
tallic oxides to form crystallizable salts. It is not poison- 
ous. In union with cyanogen, as KdCy, it is said to form 
the most violent of all poisons. 

Propyl, CfiH^; Butyl, CgHg; Amyl, CioHu; etc. 
Those are the compound radicals of the series of alco- 
hols and ethers homologous with wood-spirit and wood- 
ether. As oxides they form ethers, and as hydrated oxides 
alcohols. (Sec page 243.) Their alcohols, when oxidized, 
yield homologous acids. 
21* 



246 BENZOYL. 



Benzoyl, C14H5O,; Cinnamyl, C^.'R.O,; and Salicyl, CUH5O4. 

1. Benzoyl— ChH^O,. Symbol, Bz. 

Benzoyl is a compound radical, not as yet isolated, 
which can be made to combine directly with chlorine, hy- 
drogen, oxygen, etc., and to fulfil the part of a metal. Its 
most important compounds are — 

Hydride of Benzoyl, Bitter-Almond Oil CJ4H5O2H 

Hydrated Oxide of Benzoyl, Benzoic Acid C,4H5020,HO 

Chloride of Benzoyl Cj^HgOjCl 

Benzoic Alcohol Ci4H70,H0 

Hydride of Benzoyl — BzH. Bitter-Almond Oil This 
oil is obtained by distilling bitter almonds, after they have 
been crushed and the fixed oil expressed, with water. 
The water is essential to the formation of the oil, inas- 
much as it acts upon a crystallizable principle, called 
Amygdalin, which exists in the seed, and, aided by nitro- 
genous substances, likewise contained in the pulp, forms 
from it bitter-almond oil. 

Properties. — It is a thin liquid, of agreeable odor and 
high refractive power; its density is 1.043, and boiling 
point 356°. Exposed to the air, it absorbs oxygen with 
rapidity, and is converted into Benzoic acid. 

Benzoic Acid — BzO,IIO. It may be obtained in large 
quantities by heating some of the balsams, especially gum 
benzoin. 

Properties. — It enters readily into combination with the \ 
alkalies and metallic oxides to form soluble crystallizable 
salts. By prolonged heating with fuming nitric acid it 
forms two new acids, Nitrohenzoic, C,4(H4N 0^)03, HO and 
Binitrohenzoic, Ci4(H3(N04)2)03,HO ; in the former of 
which one atom, and in the latter two atoms of hydrogen 
are replaced by Hyponitric acid. These substitutions are 



BENZOL — ANILINE— CINNAMYL — SALICYL. 247 

of constant occurrence, and should be studied in order to 
understand important operations in manufacturing chem- 
istry. 

Benzol — CiaHg. 

Preparation. — It may be formed by decomposing Ben- 
zoic acid by Hydrate of Lime ; thus, Ci4H604+2(CaO,HO^ 
= Ci2H64-2(CaO,C02) + HO, or by distilling bituminous, 
coal (see p. 233). Benzol has recently become of great 
importance, as the source of Aniline, by the following 
series of transformations : Benzol is first converted into 
Nitrobenzol, C12H5NO4, by heating with fuming nitric 
acid, and then the nitrobenzol changed to aniline by dis- 
tillation with acetic acid and iron filings, C,2H5N04-|- 
12(FeO,C4H303) + 2HO=C,2H7N+6Fe203,12(C4H303). 

Aniline, C12H7, is an oily, colorless liquid, of density 
1.028, and boiling point 360°. It enters into combination 
with acids and forms many beautiful crystallizable salts. 
That formed with sulphuric acid, the Sulphate of Aniline, 
gives with Bichromate of Potash the exquisite mauve 
color patented by Mr. Perkins, which was the first formed 
of the many commercial aniline dyes. 

Cinnamyl — CigHyOa, Symbol Ci. 

Like benzoyl, this radical, when combined with hydro- 
gen, yields an oil, the Oil of Cinnamon, C18H7O2II. Its 
hydrated oxide forms an analogous acid, Cinnamic acid, 
Ci8H7020,HO. It unites with chlorine to form a Chloride 
of Cinnamyl, CgH^OaCl, and forms Cinnamylic Alcohol, 
C,8H90,HO, corresponding to Benzoic Alcohol, CuH^O, 
HO. 

Salicyl-CuHsO^. 

As a Hydride, CUH5O4H, Salicyl forms an oil, which 
has been found to be identical with that distilled from the 
flowers of meadow-sweet. This artificial oil has been ob- 
tained from Salicin, C^eHisO^, the bitter principle of poplar 
and willow bark. 



248 OXALIC AND TARTARIC ACIDS. 

m. VEGETABLE ACIDS. 

Tinder this section are included those acids which are 
not formed artificially by oxidation of the alcohols or by 
other means, but exist ready formed in plants. They are 
sometimes met with in the free state, but generally in 
combination with bases. The most important are — 



Oxalic Acid C^Og, 2 HO 

Tartaric Acid C8H40,o,2HO 

Citric Acid C,2H50ii,3HO 



Malic Acid C8H408,2HO 

Tannic Acid C54Hi903i,3HO 

Gallic Acid C7H03,2H0 



Oxalic Acid— C406,2HO. 

It is found in combination with potassa or lime in many 
plants, and particularly in various kinds of sorrel (^Oxalis). 

Preparation. — It may be formed by digesting any sac- 
charine or amylaceous matter with moderately strong 
Nitric acid. Thus, 1 part of Sugar, 5 parts of Nitric 
acid of sp. gr. 1.42, and 10 parts of Water, when heated 
together, yield on cooling colorless crystals of Oxalic acid. 
The nitric acid gives up its oxygen to the sugar, and we 
have C24Hi80i8+360=6(CA) + 18HO. 

Properties. — Extremely sour, very soluble in water, 
highly poisonous, and capable of combining with the alka- 
lies, earths, and metals to form crystalline salts. It is 
bibasic, and forms two series of salts, one containing 2 
equivalents of the basic body, the other 1 equivalent along 
with one atom of water. Will remove stains made by 
common ink. Sold for this purpose under the name of 
Salts of Lemon. 

Tartaric Acid— C8H,Oio,2HO. 

Found combined with potassa in many fruits, especially 
grapes, tamarinds, and pineapples. 

Preparation. — When the juices of these fruits are fer- 
mented, as in the manufacture of wine, the Acid Tartrate 
of Potassa is thrown down, and forms a coating on the 



ROCHELLE SALT — CITRIC ACID. 219 

sides and bottoms of the cask, called Argol or Tartar. 
When argol is repeatedly washed, filtered with animal 
charcoal, and crystallized, it is converted into Cream of 
Tartar, or nearly pure acid Tartrate of Potassa, KO,HO, 
C8H4O10. From this substance, by neutralization with 
lime and subsequent removal of the bases by sulphuric 
acid, Tartaric acid may be obtained. 

Properties. — Large, white, colorless, transparent crys- 
tals, readily soluble in water. Strongly acid to the taste, 
and quickly reddens litmus. It is bibasic, and, like all the 
other vegetable acids, containing 2 equivalents of basic 
water, forms two series of salts, one containing 2 and the 
other 1 equivalent of the base. 

Use. — Tartaric acid is largely employed in calico print- 
ing, to liberate from bleaching powder the chlorine neces- 
sary to bleach part of the colored print, in order to form a 
pattern. 

Its most important salts are — 

RocMle Salt— KO,NaO,C8H,0:o+8HO. Tartrate of 
Potassa and Soda. It is obtained, by neutralizing 
Cream of Tartar with Carbonate of Soda, in very soluble 
crystals. It is used as a purgative. 

Tartar-Emetic — KO,Sb03,C8H40io+4HO. Tartrate of 
Potassa and Antimony. 

Preparation. — Equal parts of Cream of Tartar and 
Oxide of Antimony are boiled with 6 parts of water. 

Use. — Largely employed in medicine. 

Effervescing mixtures are composed either of Tartaric 
acid and Bicarbonate of ^od.n. {Soda powders), or Tartaric 
acid and Bicarbonate of Soda with Rochelle Salt (^Seidlitz 
'powders). 

Citric Acid— CiAOn,3no. 

Exists in the juices of the lemon (citron) and, to a 
•smaller extent, of orange, currant, gooseberry, etc. 

Preparation. — A Citrate of Lime is formed, in the Hrst 



250 MALIC AND TANNIC ACIDS. 

place, by neutralizing lemon-juice with lime, and after- 
wards decomposed by sulphuric acid. 

Properties. — On evaporation, the citric acid thus set 
free, separates in colorless crystals of great solubility, 
strongly acid character, and agreeable taste. It is, as its 
formula indicates, tribasic. By heating with Nitric acid, 
it is converted into Oxalic acid; with Caustic potassa, 
into Oxalic and Acetic acids. 

Uses. — In calico printing ; in imparting an agreeable 
flavor to cookery ; in making effervescent drinks, and as a 
Citrate of Magnesia, for a pleasant-tasting cathartic. 

Tests. — A white precipitate with baryta, strontia, and 
lead. 

Malic Acid— C8H,08,2HO. 

Sources. — It is found in large quantities in unripe 
fruits, such as the apple {Malum), pear, plum, etc. ; also 
in vegetables, such as the rhubarb, or pie-plant. 

Properties. — Forms soluble crystals, which melt at 
181°. By heating, it is converted into two other acids, 
the maleic and paramaleic or fumaric acids, both of 
which have the formula C8H20e,2HO, and are therefore 
isomeric, that is, they consist of the same elements in the 
same proportion. 

Tannic Acid— Cs^H.^Oai.SHO. Tannin. 

Sources. — Found in the bark and leaves of the oak, 
chestnut, hemlock, and many other trees. Forms a large 
portion of nutgalls, which are excrescences upon oak 
leaves. 

Preparation. — It may be obtained by steeping pow- 
dered nutgalls in Sulphuric ether. 

Properties. — It hardens as a yellow substance, devoid 
of crystalline structure, which is soluble in water, arid of 
peculiar, astringent taste; it reddens litmus, and forms 
salts with bases ; but its acid characters are feeble. 

Uses. — With Sesquioxide of iron, it forms a Tannate, 



ORGANIC BASES. 251 

which, when mixed with gum to hold the insoluble Tan- 
nate of iron in suspension, constitutes common writing 
ink. Besides its employment in ink making, it is used in 
enormous quantities in tanning. After the hair has been 
removed from hides, they are soaked in vats containing 
oak and hemlock bark. The Tannic acid so obtained 
unites with the Gelatine contained in the hides, and 
forms an insoluble compound with it, which is the basis 
of leather. 

Gallic Acid-C,H03,2HO. 

Preparation. — It is found, along with Tannic acid, in 
vegetable bodies, and produced whenever this acid is 
exposed to the atmosphere, or boiled with Sulphuric 
acid. 

Properties. — A crystalline body, insoluble in cold, but 
very soluble in hot water. It is converted by heating 
into Pyrogallic and Metagallic acids: thus, 0711305= CO2 
+ C6H3O3 {Pyrogallic acid), and CeHsOa = HO + CeH^O^ 
{Metagallic acid). 

Uses. — A Tanno-gallate of Iron mixed with Sulphate of 
Indigo forms blue ink. Gallic and Pyrogallic acids are 
also employed to develop photographs. 



IV. ORGANIC BASES. 
I. ORGANIC ALKALIES, OR ALKALOIDS. 

Some are found ready formed, others are obtained from 
plants by destructive distillation. They are always found 
in combination with peculiar acids, forming true salts. 
All contain nitrogen. In water, they dissolve sparingly, 
readily in alcohol, and on cooling, form beautiful crys- 
tals A few however, are oily, volatile liquids. They 
have a very bitter taste, and are highly poisonous: the 
proper antidotes are animal charcoal and tannin. The 
most important are : — 



252 MORPHIA — CINCHONIA. 

Morphia C34TT,j,N06+2HO 

Narcotina , ^'48^^25^0,4. 

Cinchonia C40H24N2O2. 

Quinia ^4o^^2i^2^A- 

Stryclinia C42H22N204- 

Brucia 046^26^208. 

Veratria Og4H52N20j5. 

Caffeine Ci6H,6N404. 

Conia CieHj^NOg. 

Nicotina CiqH^N. 

Morphia— C3,Hi9N06+ 2H0 (crystallized). 

Sources. — Exists along with narcotina, codeia, tJiebaia, 
papaverina, opianine, resin, oil, gum, etc., in opium, or 
dried poppy-juice. They are found in combination with a 
peculiar acid, the meconic (from mecone, a poppy). In 
100 parts of opium, there are 1 per cent, of Meconic acid, 
10 of Morphia, and T of Narcotina. 

Preparation. — It is separated by digesting opium for 
several days in alcohol, and precipitating by ammonia. 
The morphia thus obtained, is purified by solution in boil- 
ing alcohol, from which it deposits on cooling. 

Properties. — It crystallizes in brilliant rectangular 
prisms, which contain 2 equivalents of water of crystal- 
lization. At a gentle heat the water is driven off, and 
the morphia solidifies into a resinous mass. It requires 
1000 parts of cold, or 400 of hot water for solution ; of al- 
cohol, only 30 parts ; dissolves also in acids, fixed alka- 
lies, and alkaline earths. 

Use. — In doses of J to J of a grain employed in medi- 
icine ; so likewise the Sulphate, Muriate, and Acetate of 
Morphia. 

Tests. — Colored green by mixture of Nitric and Sul- 
phuric acids ; blue by neutral solution of Perchloride of 
Iron. 

CincliGiiia, C4oIl24N,02, and Quinia, C4oH24N'204. 

Source. — They are found associated together in the bark 



QUINIA AND ISOMERIC BODIES. 253 

of the Cinchona tree, which g^rows extensively in South 
America, and is known in commerce as Peruvian bark. 
The former is found most abundantly in the pa.le or Loxa 
hark ; the latter in the yellow or red, the Galisaya bark. 
They are combined with Kinic acid. 

Preparation. — The powdered bark is dissolved in al- 
cohol, the alkaloid precipitated by lime or ammonia, then 
boiled in alcohol and converted into Sulphate. From 
solution, the Sulphate of Quinia, being less soluble, crjs- 
tallizes out first. 

Properties. — Cinchonia crystallizes in very beautiful 
transparent prisms. It has strongly basic properties, and 
forms many crystallizable salts. It turns the plane of 
polarized rays to the right. 

Quinia crystallizes less distinctly, but is more soluble 
than Cinchonia. It has an intensely bitter taste; rotates 
the plane of polarization to the left. Its most important 
salts are the Muriate and 

Sulphate of Quinia, C,,B.,,J^,0 ,,110,^0,^11^0. This 
is the neutral Sulphate, but there is likewise an acid salt. 
It forms with iodine a beautiful crystalline body, which 
has the same absorbent power upon light as tourmaline, 
and may be used as a substitute for it in the polariscope. 

Uses. — Quinia is very largely employed in medicine on 
account of its febrifuge and antipcriodic powers ; Sulphate 
of Quinia to display the phenomena of fluorescence. 

Isomeric Bodies. — If these Quinia salts be exposed to 
sun-light, or treated with excess of acid, they pass into a 
resinous condition, and constitute Quinoidine. This is in 
reality a mixture of two alkaloids, one of which has the 
same properties and is isomeric with Quinia, Quinidine, 
the other isomeric with Cinchona, Ciucho)iidinc : and 
when these two substances are exposed to a temperaturo 
of 250^ they are changed into two otluM- isomeric bodies, 
Quinicine and (\)}cho)iici))e. The nu^st remarkable dif- 
22 



254 STRYCHNIA — BRTJCIA — VERATfllA. 

ference between them all is in their action upon the plane 
of polarization ; for 

Quinia produces a powerful rotation to the left. 



Quinidine " 


" 




" rigbt. 


Quinicine " 


feeble 




" right. 


Cinchona " 


powerful 




" right. 


Cinchonidine " 


" 




" left. 


Cinchonicine " 


feeble 




** right. 



Stryclmia, 0442:2,^204, and Brucia, C46H26N2O8. 

Source. — They are found associated together in the fruit 
and bark of Nux Vomica and in St. Ignatius Bean. In 
the former they are combined with lactic acid. 

Preparation. — They are precipitated by excess of hy- 
drate of lime, filtered from solution in boiling alcohol, and 
afterwards separated by cold alcohol. Strychnia crystal- 
lizes out first. 

Properties. — Small, transparent, colorless, very brilliant 
octahedrons ; soluble in QQQ'J parts cold and 2000 parts 
boiling water; very slightly soluble in cold alcohol or ether. 
Yery bitter and fearfully poisonous. 

Brucia is distinguished from Strychnia by its ready sol 
ubility in alcohol, and by giving, when its salts are mixed 
with Tartaric acid, no precipitate with Bicarbonate of 
Soda. 

Tests. — Moistened with Sulphuric acid, Strychnia gives 
with Bichromate of Potassa a beautiful violet tint, passing 
into pale rose. Brucia and its salts afford a bright scarlet 
color, gradually passing into yellow with Nitric acid ; on 
addition of Protochloride of Tin a fine violet. 

Ver atria— C 64H52N2O 16. 

Source. — Occurs principally in combination with Gallic 
acid in several varieties of Veratrum. 

Properties. — An acrid, fearful poison, producing, on 
contact with the nasal membrane, dangerous tits of 
sneezing. 



ETHYL AMMONIAS. 255 

Une. — Sedative in neuralgia, when applied as an ex- 
ternal ointment. 

Test. — Strikes with Nitric acid a red color slowly chang- 
ing to yellow. 

Caffeine, C16H10N4O4, or Theine. 

Remarkable as being found in coffee-grains and tea- 
leaves, in the leaves of Paullinia sor^bilis, and in those of 
Ilex Paraguayensis, from which the universal beverages 
are obtained. 

Conia, CigHisN, and Mcotina, CioH^N. 

They differ from all other alkaloids in forming oily, 
volatile liquids. The first is the poisonous principle of 
hemlock, the second of tobacco. 



II. ARTIFICIAL OEGAUIG BASES, OR ARTIFICIAL 
ALKALOIDS. 

The best method of studying the production and con- 
stitution of these bodies is by comparing them with am- 
monia; for, like ammonia, they all contain nitrogen, have 
alkaline properties, and are capable of combining with 
acids to form crystallizable salts. They may be consid- 
ered, indeed, as ammonia, in which one or more equiva- 
lents of hydrogen are replaced by the same number of 
equivalents of the compound radicals, ethyl, methyl, phe- 
nyl, etc. ; thus 



N^ H N^ II N^C.H 

Ih i II i II 



H fCA r^^Hg fC^TIg 

" CJI^ 



Ammonia. Etliyl-ammonia, Bictb^d-ammonia, Triethyl-aimnoiiia, 
or Etliylamine. or Biethylamine. or Triethylainino. 

The Ethyl Ammonias. 
1. Etliylamiiie-N(Cjr3)n,= CJI,N. 

Freparation. — Formed by healing strong ammonia 
with iodide of ethyl in hermetically sealed tubes: thus. 
C4H6l+Nn3=N(CJl5)ll3T, and distilling the product 



256 BIETHYLAMINE — TRIETHYLAMINE 

with caustic potash, :N(C4H5)H3l -f £0 = NcC,H5)H2+ 
HO + KL 

Properties. — A thin mobile fliiicl, strongly alkaline, and 
combining, like Ammonia, to form many crystallizable 
salts. It forms a Hydrochlora.te of ethylamine, with the 
formation of white clouds, similar to those arising from 
the combination of Hydrochloric acid and Ammonia, 
liike Ammonia, it precipitates the Salts of Alumina, 
Magnesia, Iron, Manganese, Bismuth, Chromium, Tin, 
Lead, and Mercury. 

Biethylamine— N(C4H5),H= CgHn^^ and 

Triethylamine-N(C4H5)3= C.^Hi^N. 

Pre2)aration. — They are produced by reactions analo- 
gous to those between ammonia and bromide of ethyl ; 
ethylamine, or biethylamine taking the place of the 
former: thus, ]S"(C,H5)H,+ G,H5Br=X(C4H5)2H,Br ; and 
N(C4H5)2H,Br+KO=N(C4H5)2H+HO+KBr. 

Properties. — With the increase of equivalents of the 
elements composing them, there is a corresponding rise of 
boiling point; ethylamine boiling 54.4°, biethylamine at 
133°, triethylamine at 195.8°. Their alkaline properties 
correspondingly diminish, though all form beautiful salts. 
As we have 

0,H0 so nJ ^^[Js }.o,HO. 

IC4H5J 

Hydrated oxide of ammonium. Hydrated oxide of tetretliyl- 

ammonium. 

Hydrated Oxide of Tetrethyl-ammoniuin — :Nr(C4H5)4== 

^161120-^ • 

Properties. — It is powerfully alkaline, and closely re- 
sembles potassa, or soda, combining like them with fatty 
acids to form true soaps, and with metallic salts acting 
precisely like potassa. In its excessively bitter taste, 
resembles the alkaloids proper. 




METHTL AND AMYL AMMONIAS. 25t 

The Methyl Ammonias. 



fC^Hg rC2H3 rCJTg fC^H 

nJ H N^'c^Hg NJC2B3 ^JC^a 



3 !.0,H0 



IC2H3J 

Methylamine. Bimethylamine. Trimethylamine. Hydrated oxide oi 
^CgHgN. =C4H7N. r^CgHgN. tetremethyl-am- 

monium. 

Preparation. — As hydrated cyanic acid (C^NOjHO), 
when boiled with caustic potassa, is decomposed into 2 
Eq. of Carbonic acid and 1 Eq. of Ammonia, so is Cyanate 
of Eth}^], or Methyl, into 2 Eq. of Carbonic acid and 1 
Eq. of Ethylamine, or Methylamine: thus, C2N0,H0 + 
2(KO,HO)=2(KO,C02) + NH3; and C,N0,(C,H5)0 or 
C2NO,(C,H3)0 + 2(K0,H0) =2(KO,CO0 + N(C4H5)H2; 
or N(C,H3)H,. 

Properties. — The first three are gases closely resem- 
bling ammonia. Methylamine smells slightly fishy, Tri- 
methylamine strongly so; the latter is found in consider- 
able quantity in the roe of herring. The density of Am- 
monia is 0.589, of Methylamine 1.08 ; the former is solu- 
ble in 77^0 its bulk of water, the latter in j-qq-q, and, con- 
sequently, is the most soluble of all gases. 

The Amyl Ammonias. 

rc,oH„ rc,jT„ rc.jT,, rc,on,n 

N H nJc,oH„ n C,„[I„ Nic,„n„ Olio 

Amylamine. Bianiylamine. Triamylaminc. Hydrated oxide of Te- 
=CioII,3N. =C2oH23N =<^3o^^33^' tramyl-ammonium. 

Properties. — A series of strongly alkaline bodies, whose 
basic power diminishes and boiling point increases as the 
series ascends; thus, Anniamine boils at 190.4°, Biamvl- 



amine at 338°, Triamylamine at 494.6°. 



258 ARTIFICIAL ORGANIC BASES. 

Phenyl Ammonia. 

Aniline or Plienylamine— Is^(Ci2H5)H,= Ci,H,N. 

Preparation. — When Salic^dic acid, C14H4O42HO (p 
241), is strongly heated it is decomposed into Carbonic 
acid and Carbolic acid or Phenol, C,2H602. The same 
body is found in the acid portion of coal-tar (p. 233). It 
so closely resembles the alcohols that it is assumed to be 
in composition a hydrated oxide of a compound radical, 
Phenyl, C12H5 (Sym. Pyl) ; and the body formed b}' heat- 
ing Phenol with Ammonia, Aniline, C12H7N (p. 259), has 
in like manner been regarded as a phenyl-ammonia ; thus, 
PylO,HO + NH3=2HO-fNcPyl)H2, or^d^H^N. 

Substitution-Products of Aniline. — Besides the substi- 
tution of compound radicals for the hydrogen in Ammonia, 
the hydrogen of the new artificial bases may in like 
manner be replaced by Chlorine, Bromine, Hyponitric 
acid, etc. ; thus — 

Ammonia NHg 

Aniline N(Cj^H5)IT2 

Chloraniline N(C,2H4C1)H2 

Bromaniline N(Cj2H4Br)H2 

Bibrom aniline N(Cj2H3Br2)H2 

Nitraniline N(Ci2H4N04)H2 



III. ARTIPICIAL ALKALOIDS HOMOLOGOUS WITH 
ANILINE. 

As we had a hydrocarbon Benzol, CizHg (p. 246), de- 
rived from the radical Benzoyl, CHH5O2, so likewise from 
the homologous radicals, Toluyl, CieH^O^; Xylil, CigHgO^; 
Cumyl, C20H11O2, and Cymyl, C22H13O2, result the hydro- 
carbons homologous with Benzol, CiiHg, namely, Toluol, 
CuHg*, Xylol, CgHjo; Cumol, CigHij, and Cymol, C20H14. 

And as Benzol was converted into Nitrobenzol by fura- 



ARTIFICIAL ALKALOIDS 259 

mg Nitric acid, so may its homologues be changed to 
homologous nitro-substitution hydrocarbons ; aad the ac- 
tion of Sulphuretted Hydrogen upon these last ifi the same 
as its action on Nitrobenzol, C12H5NO4, viz., G12H5NO4+ 
6HS = Ci^HjN + 4H0 + 6S. We have formed in this 
manner: — 

Benzol, CjaH^H Nitrobenzol, C,2H5N04 Aniline, N(C,2H5)H2 

Toluol, Cj^H^H Nitrotoluol, Cj^H^NO^ Toluidine, N(Ci4H7)H2 

Xylol, CigHgH Nitroxylol, C,6H9N04 Xylidine, N(C,6H9)H2 

Cumol, CigHjiH Nitrocumol, Cj8Hj,N04 Cumidine, taCis^n)^^ 

Cymol, C20H13H Nitrocymol, C20HJ3NO4 Cymidini. N(C2oH,3)H2 

Properties. — They resemble, in their deri\ ation, forma- 
tion, and properties, Aniline. They form bfedutifully crys- 
talline salts. 



IV. ARTIFICIAL ALKALOIDS CONTAINING SEVE- 
RAL COMPOUND RADICALS. 

The Hydrogen in Ammonia may not only be replaced 
by a single compound radical, but also by several different 
ones. In this manner Ethyl, Methyl, etc, may occur in 
the same artificial base: — 

Ammonia NH3 I Ethylaniline NPylAeH 

Aniline NPyllTj 1 Biethylanilinc NPylAcj 

So from 

Hydrated Oxide of Ammonium NIl40,II0 

' " Triethyl-phenyl-ammonium N(PylAc3)0,II0 

< ** Trietliyl-amyl-ammonium... N(AylAe3)0,I10 

<* *' Metliyl-bietliyl-aniyl-ammo- 

nium N(AylAo,AIo)0,nO 

" *< Mcthyl-ctbyl-amyl-plienyl- 

ammonlum N(PYlAylAo:\IoH\110 

Properties. — All these Ammonium bases are powerfully 
alkaline, and resemble strikingly the Hydrated Oxide of 
Tetretnyi-ammonium, p. 256. 



260 OILS. 



V. OILS. 

The term Oil is applied to a great variety of bodies, 
which agree in the general properties of inflammability, 
sparing solubility in water, and ready solubility in alcohol 
or ether. It is usual to associate greasiness with oils, but 
this idea requires limitation. Fixed oils (see below) are 
greasy, volatile oils are not ; they are harsh to the touch. 
Mineral oils are intermediate. And when a cork is twisted 
into a bottle containing a fixed oil it makes no noise ; in 
other oils it squeaks. 

Classification of Oils. — They are most conveniently 
divided into three classes, according to their origin, viz., 
vegetable, animal, and mineral. The latter have been 
treated, under the changes produced in lignine by decay 
and distillation (p. 233) ; the former agree so closely in all 
their properties, that they are best considered together. 

Classification of Vegetable and Animal Oils. — Vegeta- 
ble and animal oils are of two kinds, (a) fixed and (6) 
volatile; so named from producing, the former a perma- 
nent, the latter a transient, stain when dropped on paper. 
Both classes absorb oxygen ; some slowly, others so rap- 
idly as to inflame spontaneously. In consequence of this 
difference, oils are farther divided into drying — those 
which, like linseed, poppy-seed, and walnut oils, become 
bard on exposure to air — and non-drying — those rancidify- 
ing only, as olive, palm, and most animal oils. In virtue 
of their siccative properties, drying oils are largely em- 
ployed in painting. 

Sources of Oils. — Oils are found in the stems, leaves, 
and fruits of plants, but abound chiefly in the seed. In 
animals they are stored up everywhere, but principally 
just beneath the cuticle ; also in the omentum and around 
the kidneys. 

Properties. — They are generally lighter than water, the 



FJXED OILS. 261 

fixed oils varying in clensitj from 0.91 to 0.94, and the 
volatile from 0.846 to 1.097. They vary likewise in their 
melting points, some being solid at ordinary temperatures, 
others liquid. In general, the greater the proportion of 
carbon they contain the higher the melting point. 

{a) Fixed Oils, also called Fats. 

Preparation. — When found in vegetables, they are ob- 
tained by submitting the crushed seeds or other vegetable 
structure to pressure, or pressure and heat combined. 
From animals they are obtained by breaking up the adi- 
pose membrane. This may be effected sometimes by the 
decay of the cellular structure, in other cases by liquefac- 
tion and expansion of the fat, which runs out or collects, 
on boiling, at the surface of the water. 

Properties. — They are generally colorless, or of a slight 
3'ellow tinge, bleaching on exposure to light; of faint odor 
and slight taste. In some cases, however, peculiar odors 
are imparted by volatile fatty acids, as to butter by butyric 
acid, or by various ethers. They are all insoluble in 
water, and, with the exception of castor-oil, but slightly 
soluble in alcohol. In ether, the essential oils, and ben- 
zol they dissolve freely. They can be heated to nearly 
500° without much change, but beyond that point they 
are decomposed, and cannot therefore be distilled. When 
heated to about 500°, they change color and evolve 
ofifensive^odors ; at a little above 600°, they are decom- 
posed and distil, with the formation of solid and liquid 
hydrocarbons, water, fatty acids, and Acrolein, CoH^Oj — 
an excessively volatile, irritating liquid. 



262 SAPONIFICATION. 

Composition. — They all consist of carbon, hydrogen, and 
oxygen ; for example, in 100 parts of the following oils 
there are 

Carbon. Hj'drogen. Oxygen. 

Olive 77.21 13.3G 9.43 

Almond 77.40 11.48 10.82 

Linseed 76.01 11.35 12.62 

Castor 14.17 11.03 14.78 

Whale 76.13 12.40 11. 5U 

Spermaceti 78.91 10.97 10.12 

Hog's Lard 79.09 11.14 9.75 

Suet 78.99 11.70 9.30 

Butter 65.60 17.60 16.80 

The fixed oils are not composed, however, of a single 
substance, but are, for the most part, mixtures of at least 
three closely-related, proximate fatty principles, viz., 
stearin (from crrmp, suet), margarin (from {.idpyapov, a 
pearl), and oleiJi (from iXatov, oil). The two former are 
solid, the latter liquid at ordinar}^ temperatures. As the 
amount of olein increases, so does the softness of the fat, 
while the boiling point correspondingly falls. 

Saponification. — Fats and fixed oils generally are to be 
regarded as chemical salts formed by the union of certain 
organic acids, such as Stearic, Margaric, and Oleic, with a 
base called Glycerin. These salts are distinguished by the 
names Stearin, Margarin, and Olein respectively. They 
are all incapable of dissolving in, or even mixing with, 
water. If however these fats are heated with a solution 
of caustic alkali, the glycerin is displaced by the more 
powerful base, and new salts of the alkali are formed, 
which are soluble in water and are known as soaps. (See 
next page.) If to the above alkaline fat-salts a strong 
acid, such as Sulphuric, is added, the base is in turn taken 
from the acids, and the latter are then set free, and are 
found to be white crystallizable bodies soluble in warm 
water and showing an acid reaction. 



SOAP AND CANDLE MAKINQ. 263 

Stearin, CiuHnoOj^ + 3H0 = Glycerin, C6H503,3HO + 
3 Stearic acid, CacHasOg^HO ; 

Margarin, CiosHio^Oi^+SHO = Glycerin, C6H503,3HO + 
3 Margaric acid, €^4113303, HO ; 

Olein, C,hHio40,2 + 3H0 = Glycerin, CeH503,3HO + 3 
Oleic acid, C36H3303,HO. 

And, in case of palm-oil — 

Palmitin, C,oA80i2 + 3HO== Glycerin, CeH503,3HO + 3 
Palmitic acid, C32H3i03,HO. 

Process of Soap-Making. — The mixture of alkali and 
fat is heated together, by means of steam, in large iron 
vessels, called coppers. Salt water is then added to cut 
the viscid fluid so formed. The glycerin, being soluble in 
brine, is carried with it to the bottom of the copper ; the 
soap, being insoluble in both brine and water, rises to the 
surface of the latter, and is then ladled out, pressed, and 
cut into cakes. 

Process of Candle-Making. — The object to be attained 
in the manufacture of candles is to get the fatty acids in 
the free state and in a pure condition. This is eftected in 
a variety of ways: — 

1st. By making, in the first place, a soap out of fat, by 
means of lime, and afterwards decomposing this soap with 
Sulphuric acid. Sulphate of lime, being insoluble, sinks 
to the bottom, and the fatty acids rise to the surface of the 
heated liquid. 

2nd. By heating fats with Sulphuric acid. At a high 
temperature the glycerin of the fat and Sulphuric acid are 
mutuall}'" decomposed. Sulphurous and Carbonic acids are 
evolved and the fatty acids set free. 

3rd. By injecting steam at a toiiip(>rature of 500° and 
600° into heated fat, the latter is decomposed, and the 
glycerin and fatty acids, in a separate and very pure state, 
are distilled over, and may be obtained st}nirately. ^.ri;is 
is the admirable process of Air. ^Vilsou. 



264 FIXED OILS. 

Besides stearin, margarin, and olein, certain fats contain 
peculiar proximate fatty principles; thus, 

Palm-oil yields Palmitin, C102H9SO12; 

Butter yields Butyrin ; 

Beeswax yields Cerin, C,08H,08O4, and 3Iyricin, 092119^04; 

Spermaceti yields Getin, C^Jl^Oi. 

By saponification of these fatty principles, we find that 

Palmitin, Cio,H9sO,2= Ghxerin, C6H503,3HO + 3 Pal- 
mitic acid, Cs.HaiOsjHO ; 

Butyrin = Glycerin, CeHjOcSHO -f (Butyric, Caproic, 
Caprylic, and Capric acids) ; 

Cetin, C6,He404 = Oxide of Cetyl, C3.2H35O + Palmitic 
acid ; 

Cerin, Cio8H,o80i= Oxide of Cerotyl, C54H55O -f Cerotic 
acid; 

Myricin, CeoHeO^ = Oxide of Melissyl, C92H92O4 + Pal- 
mitic acid. 

Spermaceti is therefore composed, in great measure, of 
Palmitate of Oxide of Cetyl, C32H350,C32H3i03; beeswax 
of Cerotate of Ox^de of Cerotyl, C5,H530,C54H5303. These 
various compound radicals and acids are homologues of 
Methyl and Formic acid; thus — 



Butyric " 


(C2H2X3) +C2HO3, 


.HO^CgH.Og.HO 


Gaproic " 


(C^H^xS) 4- " 


=C,2H,303,HO 


Caprylic " 


(C2H2X') 4- " 


=G,6H,503,HO 


Capric " 


(C^H^XO) + " 


=C2oHi,03JIO 


Palmitic " 


(C2H,xl5)+ " 


=C3,H3,03.H0 


Margaric " 


(C2H2X16)+ " 


=C3,H3303,HO 


Stearic " 


(C^H.xH)-}- " 


-^36^3503- HO 


Cerotic " 


(C^H^x^e)-!- " 


=^3,11^03. HO 


Melissic " 


(C2l}.x29)-f 


=CeoH3,03,HO 



Glycerin, the hase in all these fat-salts, is a sweet syrupy 
liquid, of sp. gr. 1.27, which does not evaporate, but dis- 
solves freely in water. Mixed NO5 and SO3, convert it into 
nitro-glycerin, a body exploding with great violence by 
concussion, or at a temperature of 360^. 



ESSENTIAL OR VOLATILE OILS. 265 

(6) Essential, or Volatile Oils. 

The term essential is applied to volatile oils, because 
they confer distinguishing smell and properties to the 
plants composing them. 

Preparation. — These Essential oils are found in the 
leaves, flowers, fruits, and seeds of plants. In some cases, 
as the orange-tree, the leaves, flowers, and fruit each yield 
a distinct oil. They are generally obtained by distilling 
the plant with water, the plant being in some cases fresh, 
in others salted or dried. When it is inclosed in cellular 
structure, as of orange or lemon-peel, it is procured by ex- 
pression. Though the boiling-points of these oils is above 
the boiling-point of water, they are carried over with steam 
at 212°, and condensed with it in a refrigerator attached 
to the still. 

Most of these oils are lighter than water, and float in a 
pure condition upon the surface of the water in the refrig- 
erator; a portion, however, of the oil is always held in 
solution, constituting what is termed 
'perfumed or medicated waters. To sep- 
arate the oil from the perfumed water, 
they are poured into a Florentine re- 
ceiver. It is conical in form, and at the 
side is a spout, b c, communicating with 
the bottom, the orifice c of the spout 
being much lower than the mouth a of 
the receiver. The distilled product being 
poured into this vessel, the oil B separates from the water 
A, and occupies the upper part of the vessel. The water, 
as it rises above the bend of the spout, flows off at c, while 
the Essential oil may be from time to time removed by 
means of a pipette. 

When the oil, as happens with that from jasmine, violet, 
tuberose, narcissus, etc., is too small in quantity and too 




266 ESSENTIAL OILS. 

delicate to be collected by expression or distillation, the 
flowers are laid between woollen cloths saturated with an 
inodorous fixed oil. The latter absorbs the essential oil 
of the flowers, and afterwards, by digesting the cloths in 
alcohol, an essence is obtained, free from fixed oil, which 
is insoluble in alcohol. 

Essential oils are mostly colorless when newly made 
and pure, but by absorption of oxygen they become yellow 
or brown, and even in some cases green and blue. Some 
of them, however, are bleached on exposure to light. 

They are generally of an agreeable odor, strongly aro- 
matic and even burning flavor, and a few are poisonous. 
They dissolve freely in ether and alcohol, and mix in all 
proportions with fixed oils. 

Classification of Essential Oils. — They are divided ac- 
cording to their composition, into 

(a) Hydrocarbon Oils, composed of Carbon and Hy- 
drogen ; 

(6) Oxyhydrocarbon Oils, composed of Carbon, Hydro- 
gen, and Ox3^gen ; 

(c) Essential Oils containing Sulphur, 

Most of the essential oils, however, are mixtures of a 
and b, and in many cases the latter, when isolated, is a 
solid, resembling camphor. To the hydrocarbon Berze- 
lius gave the name s^earop^ene, and to the oxyhydrocarbon, 
elaioptene from areap, fat, or iT^aiov, oil, and xtrjvb?, volatile). 
They may be separated by cold, which converts the cam- 
phor into a solid, or by distillation, when the hydrocarbon 
passes over first. 

By exposure to air the Essential oils suffer two kinds of 
cnanges : some absorb oxygen, and form with it crystal- 
line and oftentimes acid compounds ; others part with a 
portion of their hydrogen, which forms with oxygen water, 
jind solidify into resins. 

By the action of Chlorine, Iodine, and Bromine, Hy- 



OIL OF TURPENTINE. 267 

drochloric, Hydriodic, and Hydrobromic acids are formed, 
along with compounds of these gases and acids, with the 
remaining portion of the oil. In violent changes, some- 
times thus produced, inflammation occurs. 

{a) Hydrocarbon Essential Oils. 

These present a remarkable sameness of composition, 
containing about 88 or 89 per cent, of carbon, and 11 or 
12 per cent, of hydrogen, and may therefore be repre- 
sented by the formula C5H4. Their different varieties 
may consequentl}^ be regarded as isomeric modifications 
of C5H4, or CioHg, or C20H16, or C40H32. All these formulae 
represent equally well the composition of the oils by 
weight, one being sometimes preferred to the other 
merely on considerations relative to their different vapor 
densities. The most important are : — 

Oil of Turpentine, Camphene, C.^oBue, and Oil of Lemon, 
CjoHg. 

Preparation. — ^The former is obtained by distilling tur- 
pentine with water, the latter by expressing the yellow 
portion of lemon-peel. Turpentine is a viscid fluid, con- 
sisting of oil of turpentine holding rosin in solution, which 
exudes at certain seasons of the year from incisions in the 
bark of pine trees. Spirits of turpentine is impure cam- 
phene containing some rosin; burning fluid is camphene 
mixed with three or four times its bulk of alcohol. 

By the action of Hydrochloric acid Camphene and Oil of 
Lemons are each converted into two artificial camphors, 
much resembling common camphor in appearance and 
properties, one of them being solid and the other liquid at 
ordinary temperatures. The oils of orange-peel, etc mi, 
bergamot, pepper, juniper, ciibebs, copaiba, etc., are sim- 
ilar in composition to the above, and are all isomeric, but 
having a dift'erent specific gravity and boiling point. 



gel 



CAMPHORS. 



(5) Oxyhydrocarbon Essential Oils. 

These comprise most of the volatile oils used for medi- 
cine and perfumery. The three most important, oil of 
bitter almonds, cinnamon, and meadow-sweet, have al- 
ready been described as hydrides of the compound rad- 
icals benzoyl, cinnamyl, and salicyl. Of the remainder, 

Oil of Aniseed consists of a fluid oil and a crystalline 
solid. C.x,Hi,0,; 

Oil of Cumin consists of Cymol, CaoH^ (liquid), and 
Curainol, Q.y^'E.xX)^ (liquid) ; 

Oil of Thyme consists of several substances, chiefly 
Thymol, Q,^,,0, (solid) ; 

Oil of Rue consists of several substances, chiefly the 
liquid C20H20O0 ; 

Oil of Cedar-wood consists of Cedrene, C30H04 (liquid), 
and the solid Cs.Ho^O^ ; 

Oil of TTinter-green consists of Salicylate of Oxide of 
Methyl, CuH,0,,HO,MeO ; 

Oil of Talerian, consists of Yalerol, C12H10O2, Borneene 
(a camphor), and Taleric acid. 

Properties. — It will be observed that these oils are gen- 
erally composed of a fluid portion, which is a hydrocarbon, 
and a solid, containing, in addition to carbon and hydro- 
gen, oxygen. The latter, by oxidization, may sometimes 
be changed to acids. These solid essential oils, or stea- 
roptens, are sometimes included under the general head of 

CAMPHORS, 

From their close resemblance to the two crystalline ox- 
idized essences, originally known under this name, viz., 
Japan Camplior, C^oHigOo, and Borneo Camphor, CaJTijOa 
Preparation. — The former is obtained by distilling with 
water the roots and leaves of the Lairrus camphora, a tret* 



RESINS AND BALSAMS. 269 

found chiefly in Japan ; the latter from the Drydbalanops 
.caniphora, a native of Borneo. 

Properties. — They dissolve sparingly in water, abun- 
dantly in alcohol and ether. When enclosed in a glass 
vessel they vaporize, and are afterwards condensed in 
small crystals upon the side of the vessel which is ex- 
posed to the light. In contact with Nitric acid the 
former is oxidized to Camphoric acid, C2oHi406,2HO ; 
the latter to Japan Camphor. By action of oxygen on 
volatile oils still another class of allied substances is 
formed, the 

RESmS AND BALSAMS. 

The type of this class is common rosin, or colophony y 
which is formed by the abstraction of 1 equivalent of hy- 
drogen in Oil of Turpentine by the oxygen of the air to 
form water; thus. Oil of Turpentine, C2oHi6+0=C2oHi5-|- 
HO ; and further oxidation of the body thus formed, C20H15, 
to Pinic and Sylvic acids, both of which have the formula 
C20H15O2. A mixture of these two acids constitutes rosin. 

Lac, or Gum Lac, as it is frequently termed, exudes from 
the punctures made in the Ficus tree by insects. It is 
soluble in alcohol, oil of turpentine, and hot solution of 
borax. It is of very complex composition, consisting of no 
less than five different resins. Largely used in varnishes, 
in hat making, and forms the chief part of sealing-ivax. 
Its most important varieties are Stick-lac, Seed-lac, and 
Shellac. 

Mastic, Dammar-resin, Sandarac, and Copal, are resin- 
ous products from trees growing in hot climates. They 
are largely employed in varnishes. 

Amber is a resin which has exuded, in some past geo- 
logical era, from trees now extinct, and which is cast up 
on the shores of the Baltic and the coast of Now Jorsoy 
23* 



2*70 ESSENTIAL OILS CONTAINING SULPHUR. 

in masses of a few ounces in weight. It is fashioned on 
the lathe into ornaments, and is made into v^arnish. 

Caoutcliouc, or Grum-elastic, India-rubber, and Gutta 
Percha — are the dried juices of certain tropical plants. 
They are insoluble in water and alcohol; sparingly 
soluble in ether and the essential oils. Largely soluble 
in chloroform. In oil of turpentine, especially when 
holding sulphur in solution, Caoutchouc dissolves to a 
viscid, sticky substance. By heating with sulphur the 
elasticity of Caoutchouc is increased, and it is rendered 
less liable to be affected by differences of temperature. 
The new substance thus formed, and which is known 
as Vulcanized India-rubber, is employed in the manu- 
facture of combs, brushes, knife-handles, etc. 

The Balsams, such as Venice Turpentine, Canada Bal- 
sam, etc., are natural solutions of resins in essential oils. 
Some, as Feru and Tolu Balsams, and Gum Benzoin, 
contain in addition benzoic or cinnamic acid. 



(c) Essential Oils Containing Sulphur. 

The two most important of this class are : — 

Oil of Black Mustard, CgHsNSa, and 

Oil of Garlic, CMS- 

Preparation. — The former does not pre-exist in the seed, 
but is formed in the process of distillation by the joint 
action of water and Myronic acid upon the pulpy matter 
of the bruised seed, after the fixed oil which it contains 
has been expressed. (See Oil of Bitter Almonds, p. 246.) 

Composition. — Oil of Mustard is supposed to be a com- 
pound of Sulphocyanogen, C2NS2 (p. 2T3), with a hydro- 
carbon, CgHs, known as allyl, forming Sulphocyanide of 
AUyl; thus, C8H5NS,= C6H5C2NS,. 

In like manner garlic oil is regarded as a Sulphide of 
Allyl, CeH^S. 



CYANOGEN AND ITS COMPOUNDS. 211 

VI. CYANOGEN AND ITS COMPOUNDS. 

In consequence of its close resemblance to the halogens 
this important radical has already been described, p. 164. 
Like the halogens it forms one acid compound with hy- 
drogen, and many compounds with the metallic elements 
which have the properties of salts, viz.: — 

Hydrocyanic or Prussic Acid, HC^jN or HCy. (Sym. of 
Cyanogen, Cy.) 

Preparation. — Produced by decomposing Cyanide of 
Mercury with Sulphuretted Hydrogen, HgC2N + HS = 
HgS+HC,N. 

Properties. — A thin, colorless liquid, boiling at Y9° and 
freezing at 0°. It is very volatile, has a peachy odor, and 
is fearfully poisonous. Best antidote is ammonia. Its 
acid properties are very feeble. Rapidly decomposes, 
especially when exposed to light. 

Salts of Hydrocyanic Acid. — The Cyanides of Potas- 
sium and Sodium may be obtained by burning Potassium 
or Sodium in Cyanogen gas. For commercial use, how- 
ever, Cyanide of Potassium, KCy, is prepared by decom- 
position of Ferrocyanide of Potassium (p. 272). 

Cyanide of Mercury, HgCy, may be obtained by de- 
composing Cyanide of Potassium with Red Oxide of Mer- 
cury, KCy4-Hg0=K0 + HgCy. It is valuable as a source 
of Cyanogen. 

The Cyanides of Silver and Gold, AgCy and AuCya, 
Are largely employed in solution with Cyanide of Potas- 
' Bium as baths for silver and gold electro-plating. 

Compounds of Cyanogen with Oxygen. 

With oxygen Cyanogen forms three isomeric acids :^ — 
Cyanic acid, C2NO ; 
Fulminic acid, C4N2O2 ; and 



272 FERROCYANOGEN, ETC. 

Cyanuric acid, CgNsOg. 

The first is monobasic, the second bibasic, the third 
tribasic. Thus in combination with silver we have 

Cyanate of Silver, AgO,C2NO ; 

Fulminate of Silver, 2AgO,C4N202; 

Cyanurate of Silver, 3AgO,C6N303. 

Cyanic acid, C2NO, may be combined with Ammonia to 
form a crystalline Cyanate of Ammonia, 1^11^0,0^0. 
By heating or by exposure to air a little Ammonia is 
evolved, and the crystals are found to have undergone a 
wonderful change, and become urea. 

The compound of Fulminic acid with silver, 2AgO, 
C4N2O2, is a dangerously-explosive, crystalline solid. 

Compound of Cyanogen with Iron. 

Ferrocyanogen— CgNsFe, (Sym. Cfy). This radical has 
never been isolated. 

Preparation. — It may be obtained as a Ferrocyanide 
of Potassium, Ka-CeNgFe, by digesting iron filings in a 
solution of Cyanide of Potassium; Oxygen is absorbed, 
and we have 3KCy+Fe-f 0=-KO + K2,C6N3Fe. In larger 
quantities for commercial purposes, this salt is procured 
by heating the horns, hoofs, hides, or other parts of ani- 
mals with Carbonate of Potassa and iron filings. It is 
repeatedly crystallized from solution until it forms large, 
transparent, lemon-yellow crystals, known in commerce 
as Yellow Frussiate of Potash, KzCeNsFe+SHO. 

When Ferrocyanide of Potassium is added to solutions 
of metallic salts it forms oftentimes a beautifully colored 
precipitate, which is valuable as a test. The Potassium 
is simply replaced by the metal ; thus, KgCeNsFe -f 
2(CuO,N05)=2(KO,N05) + Cu,C6N3Fe. 

Hydroferrocyanic Acid — HaCfy. Like Cyanogen, this 
radical also combines with Hydrogen to form an acid 



BASIC PRUSSIAN BLUE — FERRICYANOGEN. 273 

But Hydroferrocyanic acid is entirely different from its 
corresponding cyanogen compound, being very permanent, 
and strongly acid. It is formed by decomposing Ferrocy- 
anide of Copper with Sulphuretted Hydrogen, CuaCeNaFe 
4-2HS=2CuS + H^CgNaFe. 

Remarks. — It will be observed, that in combination 
with the metals and hydrogen, Ferrocyanogen is bibasic. 

Ordinary Prussian Blue, Fe4Cfy3, is formed when Ferro- 
cyanide of Potassium is added to a Sesquisalt of Iron : 
thus, 3K2Cfy-f2(FeA,3N05)=6(KO,N05)4-Fe,Cfy3. It 
is employed both in water colors, and in oil paintings, as 
an intense blue color, but it is not permanent. Dissolved 
in water by means of Oxalic acid, it forms blue ink. 

Basic Prussian Blue, Fe^Cfya + Fe.Os, is formed by 
exposing the white precipitate, which is formed when a 
ferrocyanide is added to a solution of an iron protosalt, to 
the air. 

Perricyanogen— Ci.NgFea. Sym. Cfdy. 

Preparation. — A salt radical, isomeric with Ferrocy- 
anogen, which may be obtained as a Ferricyanide, by 
passing chlorine into a solution of Ferrocyanide of 
Potassium. 

Properties. — It combines with three equivalents of Po- 
tassium to form Ferricyanide of Potassium, or, as it is 
termed in commerce, Red Prussiate of Potash, KjCfdy, 
and with 3 equivalents of the other metals, and of hydro- 
gen. It is therefore tribasic. 

Remarks. — With a Sesquisalt of Iron, Forricyanido of 
Potassium produces no precipitate; with a Protosalt, it 
forms TurnhuWs Blue, FcgCfdy. 

A radical, termed GobaJtcyanogcn, having cobalt in 
place of iron, and similar in its properties and compounds 
to ferricyanogcn, has been formed. 

Sulphocyanogen— C2NS2. Sym. Csy. 

Preparation. — A salt radical, which nmy bo obtained 



274 ORGANIC COLORING PRINCIPLES. 

in combination with Potassium and Iron, by heating sul- 
phur with yellow Prussiate of Potash; K2C6N3Fe4-6S= 
2(KC2NS2) + FeC2NS2. 

Properties.— It forms an acid compound with h v drogen, 
Hydrosulphocyanic acid, HCsy, and unites with metals to 
form salts. Those which are soluble, give a characteristic 
blood-red color with Sesquisalts of Iron, but no precipi- 
tate. Exists in the saliva. 

i^ewary^s.— Sulphur may be replaced by Selenium, and 
Selenocyanogen and its compounds, analogous to Sulpho- 
eyanogen and the Sulphocyanides, be formed. 



VII. ORGANIC COLORING PRINCIPLES. 

All colors may be obtained from organic substances, 
but the prevailing tints are red, yellow, blue, and green, 
of very various tones and intensities. They are all de- 
rived from vegetables, with the exception of cochineal. 

The Art of Dyeing consists in applying the pigment in 
such a way that it cannot be washed off. As a general 
rule, the coloring matter has not sufiacient affinity for 
the fibre of the fabric to resist washing. Recourse must 
then be had to an intermediate body, having a strong 
attraction for both the fabric and the coloring matter, 
which may serve to fasten the two together. Such a 
body is termed a mordant, and the three principal mor- 
dants are Alumina, Oxide of Tin, and Sesquioxide of 
Iron. When an infusion of a dye-wood, like logwood, is 
mixed, for example, with alum and a little alkali, the acid 
of the alum combines with the alkali, and sets alumina 
free. The alumina then combines with the coloring mat- 
ter, forming a precipitate, technically called a lake, which 
permanently attaches itself to the fabric. Alumina and 



INDIGO. 275 

Oxide of Tin form bright, Sesquioxide of Iron, dull lakes. 
When the mordant is applied only to a portion of the 
fabric, by means of a pattern, all the coloring matter in 
the rest of the fabric can be washed out, and a figure cor- 
responding to the pattern will be left firmly fastened to 
the stuff. 

Coloring principles have, as a general rule, stronger 
affinities for animal substances, such as wool and silk, 
than those of vegetable origin, like cotton and flax. The 
most important organic coloring matters are : — 

Indigo. 

Litmus. 

Madder: Alizarin and Purpurin. 

Safflower : Carthamine. 

Brazil-wood and Logwood : Hematoxylin. 

Quercitron ; Fustic-wood ; Saffron ; Turmeric. 

Cochineal. 

Chlorophyle. 

Indigo— CieHsNO^. 

Preparation. — It is obtained by digesting the leaves of 
several species of the genus Indigofera for eight or ten 
days in water. A yellow substance is formed, which by 
oxidation changes to a deep blue, and constitutes commer- 
cial Indigo. By sublimation of the commercial, pure 
Indigo, sometimes termed Indigotine, may be obtained. 

Properties. — A tasteless, inodorous body, insoluble in 
water, but slightly soluble in alcohol. It dissolves in 
strong Sulphuric acid, and forms Sulphindigotic or Sul- 
phindylic acid, C,6H4NO,2S03,nO. This solution is used 
as a chemical test, and in dyeing. 

By deoxidizing agents, such as Protosulphate of Iron 
and Protochloride of Tin, the color of Indigo may be en- 
tirely removed, and white Indigo, Cmll,;^' 0,>, be formed. 
This unites with bases and forms with thorn soluble com- 
pounds, which are admirably adapted for dyeing purposes 



276 LITMUS — MADDER — BRAZIL-WOOD, ETC, 

By exposure these solutions become deep blue. It is on 
ibis principle that dyeing with Indigo is performed. 

By boiling powdered Indigo with Hydrate of Potassa 
it is changed to Aniline, Ci6H5N02+4(KO,HO)-f2HO= 
CiJI,N^+4(KO,C02) + 4H (p. 241). 

Litmus — Archil, Turnsol or Cudbear. These blue col- 
oring matters are obtained from the Rocella tinctoria and 
other lichens by exposing them in a moistened condition 
to the action of Ammonia. 

Properties.-^ThQ blue color of litmus is changed to red 
by acids, and restored by alkalies, and it may be used, 
therefore, to detect their presence. It is largely employed 
as a red dye. It is a compound of several principles, as 
Ficro-erythrin, C24II16O4 ; Orcein, CuHgO^ ; Rocellinin, 
CigHgOy ; and different acids. 

Madder — Alizarin and Pur pur in. 

This is the finest and most permanent of red dyes. It 
is obtained from the root of the Rubia tinctoria, which is 
extensively grown in southern France, the Levant, etc. 
Besides yellow coloring matters, it yields the beautiful 
Madder purple, or Purpurin, Ci8H606+2HO, and Madder 
red, or Alizarin, C20II6O6+4IIO. The latter is the chief 
coloring principle of madder. It is feebly acid. By oxi- 
dization with Nitric acid both are changed to Oxalic and 
Phthalic acids, CooHeOe -f 2H0 -f 80 = 2(C203,HO) + 

LieHeOs- 

By appropriate mordants Madder furnishes likewise 
brown and orangie colors, and the exquisite crimson 
known as Turkey red. 

Safflower affords a yellow and a red dye {carthamin). 

Brazil-wood and Logwood. — The former yields a crys- 
talline solid, termed brezeline, which gives with mordants 
a beautiful red ; the latter, by digestion in water, affords 
crystals of Hematoxylin, CieH^Oa. Produces with iron 



ALBUMINOUS BODIES. 211 

salts a permanent black, and with other mordants dif- 
ferent shades of purple and red. 

Bed ink is usually made by boiling about two ounces 
of Brazil-wood in a pint of water for a quarter of an hour, 
and adding a little gum and alum. 

Quercitron; Fustic-wood; Saffron; Turmeric. — Furnish 
yellow dyes. The color of Turmeric is changed to brown 
by alkalies, for which it may therefore be employed as a 
test. 

Cochineal. — A brilliant red dye, obtained by steeping 
the dried bodies of a little insect, the Coccus cacti, in 
water or alcohol. It is precipitated by alumina and oxide 
of tin, as carmine. 

Chlorophyle. — A waxy substance, of a green color, 
formed in those parts of plants which are exposed to 
light, and communicating to them their green tinge. 



VIII. ALBUMINOUS BODIES. 

The three most important are Albumen, Fibrin, and 
Casein. They all agree in yielding, as the first product 
of their decomposition by caustic alkali, protein (from pi'o- 
teuo, 1 am first) ; and some have supposed that the com- 
bination of protein with sulphur and phosphorus produced 
Albumen, Fibrin, and Casein. This is doubtful. 

Protein— C^.HnNaOa. 

A white, inodorous solid, capable of combining with 
both acids and bases. It is precipitated from its acid 
compounds by tannic acid and alkalies. 

The chemical formulae of Albumen, Fibrin, and Casein 
have not been determined, but they contain, as fir as can 
be learned with regard to bodies which, like these, are 
amorphous, in 100 parts: — 
24 



278 ALBUMEN — FIBRIN. 

Albumen. Fibrin. Casein. 

Carbon 53.5 52.7 63.83 

Hydrogen 7.0 6.9 7.15 

Nitrogen 15.5 15.4 15.65 

Oxygen 22.0 23.5 

Sulphur 1.6 1.2 

Phosphorus 0.4 0.3 



23.37 



The above analyses show that they closely agree in 
composition, and they may indeed, under certain circum- 
stances, be converted into each other. 

Albumen. 

Source. — It is found nearly pure in the white of eggs, 
from which it derives its name, in the serum of blood, and 
in vegetables. 

Properties. — It exists in two states ; as a liquid in the 
white of eggs, the humors of the eye, serum of the blood, 
etc., and as a solid in the brain and nerves of animals, and 
in the seeds of plants. In the former condition it is color- 
less, tasteless, inodorous, and soluble in alkaline solutions; 
in the latter a translucent, horny, amorphous body. Liquid 
Albumen is coagulable by heat, by nitric, sulphuric, hydro- 
chloric and metaphosphoric acids, by metallic salts, by 
astringent bodies, like tannic acid and creosote, and by 
alcohol. Owing to its coagulation by corrosive sublimate. 
Albumen is useful as an antidote. Its coagulation by 
acids is due to its combination with them as a base ; by 
metallic salts, to its union with the oxide of the metal as 
an acid. 

Fibrin. — Like albumen it exists in two states; 1st, as 
the chief component of muscular fibre, whence its name, 
in the clot of blood, etc.; 2nd, as gluten, the adhesive, 
pasty mass obtained from cereal grains after the starch 
has been removed. 

Properties. — When fresh it forms white, elastic fila- 
ments, which are tasteless, inodorous, and insoluble, ex- 



CASEIN — GELATIN — KREATIN. 2Y9 

cept in alkaline liquids. It coagulates spontaneously, and 
forms the clot in blood. The Fibrin obtained from venous 
blood, however, is not identical with that of arterial blood, 
and neither agree in composition with the Fibrin of the 
flesh. 

Casein. 

Source. — Is found in the curd of milk (caseum., whence 
its name), in the blood, and in peas, beans, and similar 
plants — vegetable Casein, or legumine. 

Properties. — It is soluble in alkaline solutions. Its 
solution in milk is due to the alkali present, and if the 
latter be removed by an acid, like lactic acid, the Casein 
coagulates and forms curd. The same effect is produced 
by the dried stomach of a calf, rennet. 

There are many other proximate organic principles con- 
taining nitrogen, such as Alhuminose, Pancreatin, Mu- 
cosin, Crystallin, MuscuUn, Ostein, Keratin, Synovin, 
Spermatin, etc, but we will consider only Gelatin and 
Kreatin. 

Gelatin. 

Source. — By the action of hot water on animal mem- 
branes, skin, tendons, and bones, they are made to dis- 
solve and to furnish solutions, which on cooling deposit a 
yielding, tremulous mass, called Gelatin. It is familiar as 
calves'-foot jelly, and in the dry state as glue and isinglass, 
or the dried swimming-bladder of the sturgeon. 

Properties. — As already mentioned (p. 251), the pro- 
cess of tanning depends upon the formation of an insoluble 
compound of the Gelatin contained in the hides with 
tannic acids. 

The Gelatin obtained from cartilages diifors from the 
above, and is termed chondrin. While Gelatin proper 
affords no precipitate with alum and acetate of lead, chon- 
drin does. 

Kreatin— C8H9N304,2HO. It is a colorless and beauti- 




280 BLOOD. 

fully crystalline body, which may be obtained frona the 
juices of the flesh. 

Of the animal fluids we shall consider, 

1. Blood. 

Description. — When freshly drawn it appears to be a 
homogeneous, red fluid, of slightly saline taste, peculiar 
odor, and somewhat unctuous touch. Under the micro- 
scope, however, it is found to consist of a nearly colorless 

Fig. 162. Fig. 163. ^^^^^^' serum of the blood, 

or liquor sanguinis, and 
^W^ multitudes of little red 

[i«?^(^^\\y^ 1 ^^^^^' ^^® ^^^ corpuscles, 
■^(q)! and colorless globules, 
(§)^^^^^ white corpuscles. Fig. 162 
shows the corpuscles in the 
blood of a frog, and Fig. 163 as they appear in human 
blood. 

On standing, the fibrin and corpuscles form a coagulum 
or clot, and leave the thin, yellowish fluid, termed serum, 
in a pure state. 

The analysis of blood gives: — 

Water 784. 

Red Corpuscles 131. 

Albumen 70. 

Salts 6.03 

Fatty substances and Extractive matters 6.77 

Fibrin 2.2 

1000.00 

The salts found in the blood are chloride of sodium and 
potassium ; carbonates, phosphates, and sulphates of po- 
tassa and soda; carbonates of lime and magnesia; phos- 
phates of lime, magnesia, and iron. 

The extractive matters are kreatin, fatty bodies like 
seroline, and cholesterin which is likewise found in bile, 
oleic, margaric, and other acids. 



BILE — SALIVA — GASTRIC JUICE — MILK. 281 

A most delicate test for blood is furnished by certain 
dark lines of absorption, seen with the spectroscope, p. 56. 
(See London Quarterly Journal of Science, April, 1865, 
p. 198.) 

2. Bile. — It is a yellow or green fluid, of unpleasant 
smell and extremely bitter taste. It consists of various 
salts, fats, mucus, and other substances found in other 
solutions, along with a peculiar fat, termed cholesterin, 
and a resinous body, bilin. 

3. Saliva. — It is characterized by the presence of a pe- 
culiar principle, termed ptyaline, and also contains sulpho- 
cyanogen. 

4. Gastric Juice. — In addition to muriatic and lactic 
acids, and various salts, the gastric juice contains pepsin, 
to which its digestive power is chiefly due. 

5. Milk consists of a watery fluid, in which are sus- 
pended globules of butter, surrounded by albuminous 
envelopes, and holding in solution various salts and milk- 
sugar. By churning these envelopes are broken, and the 
butter collects into a mass. 



APPENDIX. 



Extension has three dimensions, length, breadth, and 
thickness. These may be considered separately, in pairs, 
or all together. 

Extension in length is measured and expressed by 
certain arbitrary scales and units, shown in the follow- 
ing tables, where the relation of various units is also 
given. 





Measure of Length used in tlie United States. 




Miles. 


Furlongs. 


Chains. 


Rods. 


Yards. 


Feet. 


Inches. 


1. 


8. 


80. 


320. 


1760. 


5280. 


63360 


.125 


1. 


10. 


40. 


220. 


660. 


7920 


.0125 


.1 


1. 


4. 


22. 


66. 


792 


.003125 


.025 


.25 


1. 


6.5 


16.5 


198 


.00056818 


.0045454 


.045454 


.181818 


1. 


3. 


3G 


.00018039 


.00151515 


.0151515 


.060606 


.33333 


1. 


12 


.000015783 


.000126262 


.001262626 


.00505050 


.027777 


.083333 


1 



Length and breadth multiplied, or taken together, give 
surface. Thus, a rectangular area measuring one yard 
on each of its sides we call a square yard, and by the 
same term denote any area of equal extent, whatever its 
shape. 

(282J 



APPENDIX. 



283 



' <0 (>J (M r-( 



CD iMOl-l 
CO<M 



T-H O 



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«D O ( 



§§s; 



CC O O O Q ' 

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o o o o o < 
o o o oo ( 









^ 22 

2 C! 
a, S 





>» 






cc 


'^ 


X 


Ph 




eS 




O 


O 


*S 


a 




fl 


Si 


03 





O 


^ 



jn o 

CO >^ 






E ^ ^ 

O O) Cj 

H^ -s ^ 



,d 








l€ 


d«>Sood-;^ 


u 




^ 

p 




Q 




_; 


o S 


S 


^ g 9 








'?..'*. .<=j 


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T-l O 00 t- (M pH 


O 






lO 


















S^ 


O . ?3 iqo 


PM 


Ooc^-Oi^- • 






*: 


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^ 






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t— ■* 










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pq 


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6 





2'S 



APPENDIX. 



Dry Measure. 

4 gills = 1 pint. 

2 pints = 1 quart. 

8 quarts =^ 1 peck. 

4 pecks = 1 bushel. 

Cubic Measure. 

1728 cubic inches = 1 cub. foot. 
27 '« feet = 1 '' yard. 
128 <' " =1 cord. 
40 feet round, 50 feet square, 
timber = 1 ton. 



Liquid Measure. 


4 gills 


= 1 pint. 


2 pints 


= 1 quart. 


4 quarts 


= 1 gallon. 


16 gallons 


= I half barrel 


31| " 


= 1 barrel. 


42 " 


= 1 tierce. 


63 " 


=r 1 hogshead. 


84 «' 


= 1 puncheon. 



2 hogsheads = 1 pipe or butt. 



2 pipes 



1 tun. 



Tatle for Comparison of French and English Measures for Length. 



Metre 
Yards 
Feet 
Inches 


1 = 

1.093 
3.280 
39.390 


2 = 

2.187 

6.561 

78.741 


3 = 

3.280 

9.842 

118.112 


4 = 
4.374 
13.123 
157.483 


5 = 

5.468 

16.405 

196.853 


6 = 

6.561 
19.685 
236.224 


7 = 
7.655 
22.966 
275.595 


8 = 

8.749 

26.247 

314.966 


9 = 

9.842 

29.528 

354.337 


Decimetre 
Feet 
Inches 


1 = 

0.328 
3.937 


2 = 
0.656 

7.874 


3 = 
0.984 
17.811 


4 = 
1.312 
15.748 


5=r 
lAtO 
19.685 


6 = 
1.968 
23.622 


7 = 
2.296 
27.559 


8 = 
2.624 
31.496 


9 = 
2.952 
35.433 


Centimetre 
Inches 


1 = 
0.393 


2 = 
0.787 


3 = 

1.118 


4 = 
1.574 


5rr 
1.968 


6 = 
2.362 


7 = 
2.755 


8 = 
S.149 


9 = 
3.543 


Millimetre 
Inches 


1 = 

0.039 


2 = 
0.078 


3 = 
0.118 


4 = 
0.157 


5 = 
0.196 


6 = 
0.236 


7 = 
0.275 


8 = 
0.314 


9- 
0.354 



Example of method employed with this Table to re- 
duce French to English measure. 

Required to reduce 4612 Metres to Eeet. 

4000 Metres = 13123. feet. 

600 " = 1968.5 " 

70 '* = 229.66 " 

2 " = 6.56 " 



4672 



= 15327.72 « 



Select from the table the number corresponding fo each 
digit in the given number, assigning the proper position 
to the decimal point ; then add all these quantities j their 



APPENDIX. 



285 



sum will be the required equivalent to the quantity 
stated. 

Table for Comparison of French and English Measures of Surface. 



Hectare. 


Decare. 


Are. 


Sq. Metre. 


Square Yards. 


Square Feet. 


1 


10 


100 


10000 


11966.4 


107698. 




1 


10 


1000 


119ei.64 


10769.8 






1 


100 


119.66 


1076.98 








1 


1.19 


10.76, etc. 


Tahle for Comparison of French and English Measures of Capacity. 




Kilolitre. 


Hectolitre. 


Decalitre. 


Litre. 


Decilitre. 


Centilitre. 




1. 


10. 


100. 


1000. 


10000. 


100000. 






1. 


10. 


100. 


1000. 


10000. 








1. 


10. 
1. 


100. 
10. 

1. 


1000. 
100. 
10. 


Gallons 


220. 


22. 


2.2 


.22 


.022 


1. 


Quarts 


881.2 


88.12 


8.81 


.881 


.0881 


.00881 


Pints 


1762.4 


176.24 


17.e2 


1.762 


.1762 


.01762 


Cubic Inches 


6107-1. 


6107.4 


610.74 


61.074 


6 .1074 


.61074 



Stere 3= 1 cubic metre = 35.31658 cubic feet. 

Tahle, showing the Behavior of Solutions of Metals with Hydrosulphurio Acid 
and Hydrosulphate of Ammonia, employed successively. (Dr. Will.) The 
rarer metals are printed in italic. 



Elements precipitated from tlieir acid 
•olution by Hydrosulphukic Acid, as 


Bodies precipitated by HrDKOauLrHATK 09 Ammokia. 


lulpliides. 


^- 




-_^^^-^_ 


^ 




'Soluble in Hydro- 












sulphate of Aiiima- 


Insoluble ii 


, Hy. 










nia, and reprecipi- 


drosiilphate o 


Am- 


As Sulphides. 


As Oxide 


s. 


A« Salts. 


tated by Hydioclilo- 


nioiiia. 












ric Acid. 














''moW}"™'^"- 


Mercury ') 




Nickel ^ 


Alumina "1 




Baryta, 




^ 


Ulack 




^ 


Strontia, 




Silver 


a 


Cobalt j 


Glucina 


rS-2 


Lime, 


Arsenic^ 








^9 o 




y Yellow. 




2 '-' 






-a 


in combina- 


Tin J 


Lead 


>--l 


Manga-) Flesh- 
uoso J coloi''d. 


Chromium 




tion with 












phosphoric. 


GoUl 


Bismuth 







'Thorina 




boraoic, 






i2 








oxalic, and 


Platinum V ^ 


Copper 




Iron, Black. 


YUria 


d 


some other 


P 










acids. 


Iridium 


Cadmium, Y 


cllow 


Zinc, White. 


Cerium 


ill 


Magnesia 


'2L}>'-- 


Palladium " 




in-a- \ ■Rrown- 
«iM»i/ish-black. 


Zircon ia 


"o S 






c-^ 




c 


in conibi na- 




JiJiodium 






Titanium 




tion with 
phosphoric, 




Osmium 


M 




Tanialiuvi ^ 




acid. 



286 



APPENDIX. 



WeigM. — Three scales are in use. The Troy and 
Apothecaries' are commensurate, but the Avoirdupois has 
a dififerent standard.* 

Measures of Weight used in the United States. 

Avoirdupois. 



Tons. 


Cwts. 


Pounds. 


Ounces. 


Drachma. 


1. 

.05 

.00044642 
.00002790 
.OOU00174 


20. 
1. 

.0089285 

.000558 

.0000348 


2240. 
112. 
1. 
.0625 
.0U16 


36840. 

1792. 

16. 

1. 

.0625 


673440 

28672 

256 

16 

1 


The short ton contai 


QS 2000 lbs. 
Troy. 






Pounds. 


Ounces. 


Dwts. 


Grains. 


Pound Avoir. 


1. 

.0S3333 
.004166 
.0001736 
1.215275 


12. 
1. 

.050000 
.0020833 
14.58333 


240. 
20. 
1. 
.041666 
219.666 


5760 

480 

24 

1 

7000 


.822S61 
.068571 
.0034285 
.00020571 
1. 



Troy weight only is used in philosophical experiments. 

Apothecaries', 



Pound. 


Ounces. 


Drachms. 


Scruples. 


Grains, 


1. 


12. 


96. 


288. 


5760 


.08333 


1. 


8. 


24. 


480 


.0104166 


.125 


1. 


3. 


60 


.0034722 


.041666 


.3333 


1. 


20 


.00017361 


.020833 


.1666 


.05 


1 



* The Troy or Apothecaries* pound is to the Avoirdupois pound as 144 
is to 175, but the ounces are as 480 grains to 4371 grains Troy or Apoth- 
ecaries'. So also the Apothecaries' drachm = 60 and the Avoirdupois 
drachm =» 27^2 grains Troy or Apothecaries'. 



APPENDIX. 



287 



I 













^ 


00 


g, 




03 >A 
















1 ss 




1 S 




1 S 


1 CO II 


52 


°> s^' 


<» S 


o> « o ^ 


■• Oi 










'"' 
















ooco 




i 




^ 


s? 


^ 




1 S^ 




11 ^ II SI II 


S3 


« ^^ 


» a 


00 ^ 00 >" 


1 00 
















OS 


^ 




, ^s 




05 






o 


§ 


1 ^.t-: 




o 




5" 


3 II Q II 


rH 


*- ISS 


*- s 












i-i 
























CO 


>n 


CO 












•o 


CO 






c^o 




§ 




^ I g 11 


s 


<0 MO 


o c^ 


to 05 <o 


to 


* 




^rH 




03 














1 


^S? 


I 


?3 


I 


^ 1 


- II 






oeo 


<^» 


t- 


t- " 


o 


>« ,-ieo 


la t^ 


o t-; o 


o 






r.r. 




t- 
























os 


t- 






O5 00 




a> 




to 








.- rH 




CO 




1- 






o 




OOl- 




t- 






to II 


-^ cc d 


Tj< rH 


rH <© TJ) 


Tl4 


• 




'^ 




«o 
























t- 




CO 




t1< 00 




t- 




IM 










1 


S8 


1 


?? 


I 


£ 




^ II 


© 


CO «dod 


CO ^ 


CO Tji CO 


CO 














Tt 




00 


CO 




gs 




•* 




oc 






o 




1 


00 


1 


oc 


1 


^ li 


CO 




-*C0 


1 


oo 


1 


c 


o 


c^ nio 


- ^ 


(N ec 


(M 


<M 






II 


, 




I 


i I 


1544 






<N(M 


r- 


^ 


r-l r- 


rH 


I-H 










I-I 
















: : 
















: 
































































































: 








ra : 
























b ■ 






















c 

5 


11 

a. 


el 


1 




1 

P 




4 

E 




S 

e 

1 


c 





288 



APPENDIX. 



Table of Densities, or Specific Gravities. 
Sclids and Liquids are compared with Water at 60° 
Fahr. as 1 ; Gases with Air at 60° and Barometer at 30 
inches as 1. Air is to water, under these conditions, as 
1 to 815. 



Alabaster 1.870 

Alcohol, absolute 793 

" 95 per cent 808 

'* 85 per cent 835 

" and Water, 1:1.. .930 

Alum 1.72 

Amber 1.08 

Antimony, cast 6.71 

Ash 84 

Asphaltum 1.40 

Atmospheric Air 1.00 

Beech 85 

Bismuth, cast 9.82 

Brass, cast 8.40 

*' wire 8.54 

Camphor 099 

Carbonic Acid Gas 1.52 

Chlorine 2.47 

Coal, from 1.24 to 1.30 

Cobalt and Nickel, cast.... 7.81 

Copper, cast 8.85 

wire 8,89 

Cork 24 

Diamond 3.50 

Ebony 1.33 

Fir 65 

Flint 2.59 

Fluor Spar 3.19 

Garnet, Bohemian ..3. 69 to 3.80 

Glass, Flint, French 3.20 

« " English 3.37 

«* " Frauenhofer 3.77 

" Bottle 2.60 

'• Plate 2.37 

25 



Gold, hammered 19.36 

" pure and cast 19.25 

Gum Arabic and Honey.. 1.45 

Hen's Egg 1.05 

Hydrogen Gas 069 

Ice 93 

Iron, cast 7.20 

Iron, malleable 7.79 

Isinglass 1.11 

Ivory 1.91 

Jasper 2.70 

Jet.... 1.24 

Lead, cast 11,35 

Lignum Virae 1.33 

Lime, Carbonate of 2.71 

Linseed Oil 094 

Mahogany 1.06 

Mercury 13.59 

Muriatic Acid 1.20 

Naphtha 84 

Nitre 2.00 

Nitric Acid, concentrated 1.45 

Oak, dry, heart 1.17 

Olive Oil 91 

Oxygen Gas 1.10 

Parian Marble 2.34 

Phosphorus 1.77 

Platinum, cast 19.05 

hammered 23.00 

♦' drawn into wire 21.04 

Plumbago 2.55 

Poplar 38 

Rock Crystal 2.65 

Salt, common 2.13 



APPENDIX. 



289 



Silver, hammered 10.51 

** pure and cast 10.47 

Steel, hammered 7.81 

" soft 7.80 

Sugar, white 1.61 

Sulphate of Baryta 4.43 

** Lime 2.32 

Soda 2.20 

Sulphur, native 2.08 



Sulphuric Ether 71 

Sulphuric Acid, concentra- 
ted 1.84 

Tallow 94 

Tin, cast 7.30 

Water, fresh 1.00 

Water, Sea 1.02 

Wax, White 97 

Zinc, cast 7.20 



Table of Tenacities, or Breaking Weights. 

Selected from Journal of Franklin Institute, Vol. 40, p. 340. 
Power required to tear asunder one Sq. Inch, in Avoirdupois Pounds. 



Copper, wrought 34,000 

cast 24,250 

wire 61,200 

Gold, cast 20,000 

Iron, cast. Low Moor... 14,067 

*' Mean of American 31,8..i9 

" wire 103,000 

«' bar, Swedish 72,000 

" " English 56,000 

** boilerplate 51,000 

Lead, cast 1,800 

«♦ milled 3,320 

" wire 2,580 

Platinum, wire 2,680 

Silver, cast 40,000 

Steel, cast, maximum ... 142,000 

" spring 72,500 

'« plates, lengthwise 96,300 

** ♦' crosswise. 73,700 

" razor 150,000 

Tin, cast 5,000 

Zinc, cast 3,500 

'► sheet 16,000 

Brass 42,000 

" yellow. 18,000 

Bronze 17,698 to 56,788 

Gun-metal (Cu8:Stl) 30,000 

25 



Ash 12,000 to 16,000 

Beech 11,500 

Box 20,000 

Cedar 11,400 

Chestnut, Sweet 10,500 

Locust 20,500 

Mahogany 21,000 

Spanish 12,000 

Oak, white, American.... 11,500 

" English 10,000 

Pine, white 11,800 

Poplar 7,000 

Teak, Java 14,000 

" African 17,000 

Walnut 7,800 

Willow 18.000 

Brick 290 to 750 

Chalk 118 

Cement, Portland 400 

Glass, plate 9,400 

" crown 6,000 

Ivory 16,000 

Rope, Manilla o,'J00 

" hemp 6,400 

*« wire 87,000 

Mortar 51} 

Sandstone 20<^ 



290 



APPENDIX. 



Table for converting Degrees of Centigrade into Degrees of 
Fahrenheit. 



Cent. 

100° 
99 
98 
97 
96 
95 
94 
93 
92 
91 
90 
89 
88 
87 
86 
85 
84 
83 
82 
81 
80 
79 
78 
77 
76 
75 
74 
73 
72 
71 
70 
69 
68 
67 
66 
65 
64 
63 
62 
61 
60 
59 
58 
57 
56 
55 



Fahr. 

-148.0° 

146.2 

144.4 

142.6 

140.8 

139.0 

137.2 

135.4 

133.6 

131.8 

130.0 

128.2 

126.4 

124.6 

122.8 

121.0 

119.2 

117.4 

115.6 

113.8 

112.0 

110.2 

108.4 

106.6 

104.8 

103.0 

101.2 

99.4 

97.6 

95.8 

94.0 

92.2 

90.4 

88.6 

86.8 

85.0 

83.2 

81.4 

79.6 

77.8 

76.0 

74.2 

72.4 

70.8 

68.8 

67.0 



Cent. 


Fahr. 


Cent. 


Fahr. 


—540 


= —65.2° 


—8° 


= 4-17.60 


53 


63.4 


7 


19.4 


52 


61.6 


6 


21.2 


61 


59.8 


5 


23.0 


50 


58.0 


4 


24.8 


49 


56.2 


3 


26.6 


48 


64.4 


2 


28.4 


47 


52.6 


—1 


= 30.2 


46 


60.8 





32.0 


45 


49.0 


4-1 


= 33.8 


44 


47.2 


2 


35.6 


43 


45.4 


3 


37.4 


42 


43.6 


4 


39,2 


41 


41.8 


5 


41.0 


40 


40.0 


6 


42.8 


39 


38.2 


7 


44.6 


38 


36.4 


8 


46.4 


37 


34.6 


9 


48.2 


36 


32.8 


10 


50.0 


35 


31.0 


11 


51.8 


34 


29.2 


12 


53.6 


33 


27.4 


13 


55.4 


32 


26.6 


14 


57.2 


31 


23.8 


15 


59.0 


30 


22.0 


16 


60.8 


29 


20.2 


17 


62.6 


28 


18.4 


18 


64.4 


27 


16.6 


19 


66.2 


26 


14.8 


20 


68.0 


25 


13.0 


21 


69.8 


24 


11.2 


22 


71.6 


23 


9.4 


23 


73.4 


22 


7.6 


24 


76.2 


21 


6.8 


25 


77.0 


20 


4.0 


26 


78.8 


19 


2.2 


27 


80.6 


18 


= —0.4 


28 


82.4 


17 


= +1.4 


29 


84.2 


16 


3.2 


30 


86.0 


15 


5.0 


31 


87.8 


14 


6.8 


32 


89.6 J 


13 


8.6 


33 


91.41 


12 


10.4 


34 


93.21 


11 


12.2 


35 


95.01 


10 


14.0 


36 


96.81 


9 


16.8 


37 


98.6 



APPENDIX. 



291 



Conversion of Centigrade into Fahrenheit— coH^tnuctf. 



Fahr. 

4-100.4° 
102.1 
104.0 
105.8 
107.6 
109.4 
111.2 
113.0 
114.8 
116.6 
118.4 
120.2 
122.0 
123.8 
125.6 
127.4 
129.2 
131.0 
132.8 
134.6 
136.4 
138.2 
140.0 
141.8 
143.6 
145.4 
147.2 
149.0 
150.8 
152.6 
154.4 
156.2 
158.0 
159.8 
161.6 
163.4 
165.2 
167.0 
168.8 
170.6 
172.4 
174.2 
176.0 
177.8 
179.6 
181.4 
183.2 
185.0 



Cent. 

4-86° 

87 

88 

89 

90 

91 

92 

93 

94 

95 

96 

97 

98 

99 

100 

101 

102 

103 

104 

105 

106 

107 

108 

109 

110 

111 

112 

113 

114 

115 

116 

117 

118 

119 

120 

121 

122 

123 

124 

125 

126 

127 

128 

129 

130 

131 

132 

133 



Fuhr. 

4-186.8° 
188.6 
190.4 

• 192.2 
194.0 
195.8 
197.6 
199.4 
201.2 
203.0 
204.8 
206.6 
208.4 
210.2 
212.0 
213.8 
215.6 
217.4 
219.2 
221.0 
222.8 
224.6 
226.4 
228.2 
230.0 
231.8 
233.6 
235.4 
237.2 
239.0 
240.8 
242.6 
244.4 
246.2 
248.0 
249.8 
251.6 
253.4 
255.2 
257.0 
258.8 
260.6 
262.4 
264.2 
266.0 
267.8 
269.6 
271.4 



Cent. 



Fahr. 



4-134° 


= 4-273.2° 


135 


275.0 


136 


276.8 


137 


278.6 


138 


280.4 


139 


282.2 


140 


284.0 


141 


285.8 


142 


287.6 


143 


289.4 


144 


291.2 


145 


293.0 


146 


294.8 


147 


296.6 


148 


298.4 


149 


300.2 


150 


302.0 


151 


803.8 


152 


305.6 


153 


307.4 


154 


309.2 


155 


311.0 


156 


312.8 


157 


314.6 


158 


316.4 


159 


318.2 


160 


320.0 


161 


321.8 


162 


323.6 


163 


325.4 


164 


327.2 


165 


329.0 


166 


330.8 


167 


332.6 


168 


334.4 


169 


336.2 


170 


338.0 


171 


389.8 


172 


341.6 


173 


343.4 


174 


345.2 


175 


347.0 


176 


348.8 


177 


350.6 


178 


352.4 


179 


854.2 


180 


356.0 


181 


857.8 



292 



APPENDIX. 



Conversion of Centigrade into Fahrenheit. — Continutu. 



Cent. 

4-182° 
183 
184 
185 
186 
187 
188 
189 
190 
191 
192 
193 
194 
195 
196 
197 
198 
199 
200 
201 
202 
203 
204 
205 
206 
207 
208 
209 
210 
211 
212 
213 
214 
215 
216 
217 
218 
219 
220 
221 
222 
223 
224 
225 
226 
227 
228 
229 



Pahr. 

+359.60 
361.4 
363.2 
365.0 
366.8 
368.6 
370.4 
372.2 
374.0 
375.8 
377.6 
379.4 
381.2 
383.0 
384.8 
386.6 
388.4 
390.2 
392.0 
393.8 
395.6 
397.4 
399.2 
401.0 
402.8 
404.6 
406.4 
408.2 
410.0 
411.8 
413.6 
415.4 
417.2 
419.0 
420.8 
422.6 
424.4 
426.2 
428.0 
429.8 
431.6 
433.4 
435.2 
437.0 
438.8 
440.6 
442.4 
444.2 



Cent. 

4-230° 
231 
232 
233 
234 
235 
236 
237 
238 
239 
240 
241 
242 
243 
244 
245 
246 
247 
248 
249 
250 
251 
252 
253 
254 
255 
256 
257 
258 
259 
260 
261 
262 
263 
264 
265 
266 
267 
268 
269 
270 
271 
272 
273 
274 
275 
276 
277 



Fahr. 

-^446.0° 
447.8 
449.6 
451.4 
453.2 
455.0 
456.8 
458.6 
460.4 
462.2 
464.0 
465.8 
467.6 
469.4 
471,2 
473.0 
474.8 
476.6 
478.4 
480.2 
482.0 
483.8 
485.6 
487.4 
489.2 
491.0 
492.8 
494.6 
496.4 
498.2 
500.0 
501.8 
503.6 
505.4 
507.2 
509.0 
510.8 
512.6 
514.4 
516.2 
518.0 
519.8 
521.6 
523.4 
525.2 
527.0 
528.8 
530.6 



Cent. 



Fahr. 



-278° 


= 4-532.40 


279 


534 2 


280 


536.0 


281 


537.8 


282 


539.6 


283 


541.4 


284 


543.2 


285 


545.0 


286 


546.8 


287 


548.6 


288 


550.4 


289 


552.2 


290 


554.0 


291 


555.8 


292 


557.6 


293 


559.4 


294 


561.2 


295 


563.0 


296 


564.8 


297 


566.6 


298 


568.4 


299 


570.2 


300 


572.0 


301 


573.8 


302 


575.6 


303 


677.4 


304 


579.2 


305 


581.0 


306 


582.8 


307 


584.6 


308 


686.4 


309 


588.2 


310 


590.0 


311 


691.8 


312 


593.6 


313 


695.4 


314 


597.2 


315 


699.0 


316 


600.8 


317 


602.6 


318 


604.4 


319 


606.2 


320 


608.0 


321 


609.8 


322 


611 6 


323 


613.4 


324 


615.2 


325 


617.0 



APPENDIX. 



293 



Conversion of Centigrade into TahreuTieit.— Concluded. 

Cent. Fahr. Cent. Fahr. Cent. Fahr. 

+326° 
327 
328 
329 
330 
331 
332 



Fahr. 
+618.8° 


620.6 


622.4 


624.2 


626.0 


627.8 


629.6 


631.4 



-334° 


= +633.2° 


+342° 


= +647.6< 


335 


635.0 


343 


649.4 


336 


636.8 


344 


651.2 


337 


338.6 


345 


653.0 


338 


640.4 


346 


654.8 


339 


642.2 


347 


656.6 


340 


644.0 


348 


658.4 


341 


645.8 


349 


660.2 



Referred to on page 51. 

To prepare a double-image prism of Iceland spar, we 
take a natural crystal of that substance, and using the 
natural face, B Y, Fig. 40 ; for one surface cut a pointed 
wedge from it so that the apex of said wedge shall be in 
the obtuse angle, Y, and the new face make with the 
natural one an angle of 8° to 10°. We then prepare a 
small prism of glass, having a little less angle, to correct 
the color dispersion of the spar prism, and cement these 
together with Canada balsam as usual. 

Iceland spar may be cut first with a fine saw, then 
trimmed down with a file, " 2nd cut, bastard," then ground 
with the greatest care with emery of increasing fineness, 
and, lastly, polished with a little crocus or rouge on lea- 
ther. The best specimens of this work which I have 
ever seen, among hundreds by French and English 
makers, are prepared by J. Zentmeyer, Optician, of Phil- 
adelphia, who, I believe, is also the first successfully to 
work that difficult material in this country. 

25* H. M. 



LAWS OF CHEMICAL COMBINATION. 



Referred to on page 125. 

LAW L 

The same substance is always composed of the same 
elements in the same proportions. Thus, water, whether 
found in the blood of animals, the sap of plants, in mine- 
rals or chemical salts, in springs, rivers, the ocean or 
the clouds, consists always of Oxygen and Hydrogen 
combined, in the proportion of 8 parts by weight of the 
first to one of the second. 

LAW n. 

Each element has a certain proportion or number of 
parts by weight, in which it combines with others. This 
proportion is called its Equivalent, or Atomic Weight 
(being supposed to represent the relative weight of its 
final particle or atom). In these equivalent propor- 
tions (or in simple multiples of the same), elements will 
combine together, and in no other ratio. Thus, the 
equivalent of Nitrogen is 14, and that of Oxygen is 8 ; 
if, then, we bring together the bodies in this propor- 
tion they will combine, leaving no residue ; but if we 
have 9 parts of Oxygen, then one part of this would 
(294) 



APPENDIX. 295 

be left out, and would not enter into combination with 
the Nitrogen. We may, however, have a double equiva- 
lent of Oxygen, i.e. 16 parts, combining with the 14 of 
Nitrogen ; or a triple, 24 parts, or a quadruple, etc. Each 
of these compounds would then, however, be quite a dif- 
ferent substance from the others. 

LAW m. 

The equivalent of a compound is equal to the sum of 
the equivalents of its constituents. Thus, the equivalent 
of water made of Oxygen 8, and Hydrogen 1, is 9. 
That of Nitric Acid, made of Nitrogen 14, and 5 times 
that of Oxygen (8), or 40, is 54 (NO5 . Eq. 54.) 

LAW IV. 

Like classes of bodies combine, with each other — 
Element with element. Binary with binary, Ternary with 
ternary. Thus, Zinc can combine with Oxygen, or some 
other element, but not with Sulphuric Acid (SO3), or 
other binary compound ; but Oxide of Zinc (ZnO), itself 
a binary, can combine with the binary Sulphuric Acid. 

LAW V. 

(a) When elements unite, the electro-positive by pre- 
ference combine with the electro-negative. (6) When 
binaries unite, the electro-negative element in each must 
be the same, (c) When ternaries unite, the electro-neg- 
ative binary must be the same, i.e. they must have the 
same acid. 

Examples. — (a) Iron, which is positive, will unite 
more readily with Sulphur or Carbon, which are nega- 
tive, than with Hydrogen, which is positive, (b) Again, 
in Oxide of Iron (FeO) the Oxygen is the negative ele- 



296 APPENDIX. 

ment ; so also it is in Sulphuric Acid (SO3) ; these may 
then combine ; not so, however, Oxide of Iron and Hy- 
drocloric Acid (HCl), where Oxygen is the negative 
element in one, and Chlorine in the other, (c) Lastly. 
Sulphate of Potash (KO.SOg) may unite with Sulphate 
of Copper (CuO,S03), having the same acid, but not with 
Nitrate of Copper (CuO,N05), which has Nitric Acid for 
its negative binary. 

It is found with regard to gases, that not only is their 
combining weight fixed, as we have already shown, but 
that they have a like relative combining volume. Thus, 
Oxygen and Hydrogen unite in the proportion of one 
volume of the first to two of the second. Hydrogen and 
Chlorine in equal volumes, and so with others. Various 
attempts have been made to carry out this observation 
to solid and liquid bodies by finding or assuming their 
vapor volumes, and many elaborate deductions have been 
made from these data; but the subject is far too compli- 
cated to be discussed in such a work as the present. 



The Holtz Electrical Machine. 

From its identity in general principle, this instrument 
has been appropriately called " the continuous electropho- 
rus." Among many varieties in form which have been 
introduced, we select for description that devised and 
manufactured by Mr. E. S. Ritchie of Boston. 

A large plate of thick glass, supported in an upright 
position by carved wooden brackets, serves as the frame 
or sustaining element of the machine. A journal, attached 
to its centre, carries one end of an axle, which supports a 
circular plate of thin glass. Through the same thick glass 
plate, pass four wires or rods terminating in rows of points 
or combs, directed towards the inner face of the thin glass 



APPENDIX. 



29t 



revolving plate. Beyond this thin plate or wheel, are 
supported (by short columns from the thick glass plate) 




four glass sectors, each having at one edge (opposite one 
of the combs or rows of points) a strip of paper provided 
with a projecting point of card. The operation of the 
machine is as follows. Having given motion to the revolv- 
ing plate, so that its surface is always moving towards the 
points of card, we excite one of the paper strips or elements, 
by holding near it an excited body, such as a strip of hard 
rubber charged by friction on a piece of fur. The paper 
being charged, say negatively, repels negative electricity, 
from the further side of the revolving plate into the comb 
opposite ; attracting of course positive fluid from the comb 
to the revolving plate. The plate thus proceeds, charged 
positively on its further side. When however it comes 
near the card point of the next paper element, the positive 



298 



APPENDIX. 



charge on the further side drives positive fluid into this 
point and so into the paper connected with it, which thus 
becomes positively charged. This paper then, in the same 
way as the first, but in an opposite sense being oppositely 
charged, drives positive fluid from the rotating plate into 
the opposite comb, and drawing back negative fluid, charges 
the rotating plate negatively. The charge of the rotating 
plate is thus reversed at each quadrant, and the charge in 
the papers is increased, until it reaches a maximum. By 
various connections of the combs, different effects of quan- 
tity and intensity may be obtained, and we may either 
obtain free electricity for the exhibition of experiments in 
attraction and repulsion, or a circuit, resembling the ordi- 
nary action of the induction coil. 



Wilde's Magneto-Electric MacMne. 




In this instrument advantage is taken of the fact that 



I 



APPENDIX. 299 

when a bar of iron is magnetized by a galvanic current, 
time is required to produce the effect, and thus the influ- 
ence of successive portions of the current is accumulated, 
some beginning to act, others in full force, and others 
diminishing. From this it follows that if a series of mo- 
mentary currents (such as may be obtained from the mag- 
neto-electric machine described at p. 116) is passed through 
the coil of a large electro-magnet (see p. 93), the magnetic 
force developed by the successive currents or pulses, will 
accumulate to a degree only limited by the number of such 
pulses which it may be possible to transmit during the 
time that the effect of any one of these currents endures. 

A small machine actuated therefore by magnets of 
feeble lifting-power, may thus produce a magnetic effect 
in a large electro-magnet, by which it will be able to raise 
a weight enormously greater than that representing the 
power of the actuating magnets {e. g. 20 or 30 times). 

But this lifting-power is again synonymous with any of 
the other effects of galvanic currents under the appropriate 
conditions. Thus in the instrument figured above, a row 
of small horse-shoe magnets excite currents in a Sieman's 
armature rotated between them. (The Sieman's armature 
consists of a cylinder of soft iron with two deep grooves 
cut along its entire length, so that its cross section is re- 
presented by H J and having insulated wire wound in the 
groove.) The current developed in the coil or wire of this 
armature is passed through the coils of the great electro- 
magnet placed below, which consists of two flat plates of 
iron, wound, as indicated in the cut, with copper wire. 
Between the poles of this in like manner is revolved (by 
a belt shown in part at the right of the cut) another and 
much larger Sieman's armature, from which the current 
may be carried to a yet larger magnet, or used at once. 



INDEX. 



Absorption bands page 56 

Acetal 238 

Acetate of Allumina 239 

" Copper 239 

" Lead 239 

Acetic, Acid 238 

Acetone 239 

Acid, Acetic 238 

Benzoic 246 

Bi-nitro-benzoic 246 

Boracic 165 

Butyric 235,264 

Camphoric 269 

Capric 264 

Caproic 264 

Caprylic 264 

Carbolic 234 

Carbonic 160, 161 

Chloracetic 239 

Chloric 154 

Chromic 211 

Cinnamic 247 

Citric 249 

Cyanic 271 

Cyanuric 272 

Ferric 206 

Formic 234, 241 

Fulminic 271 

Gallic 251 

Hydrated Nitric 147 

Hydrochloric 154 

Hydrocyanic 271 

Hy droferrocy anic. 272 

Hydrofluoric 157 

Hydrosulphuric 178 

(300) 



Acid, Hypochloric 164 

** Hypochlorous 154 

" Hyponitric 147 

** Hyposulphurous 172 

" Lactic 235 

" Malic 249 

" Margaric 262, 263 

<' Meconic 252 

" Melissic 264 

«' Metagallic 251 

'< Metastannic 223 

" Nitric .. 147 

" Nitro-benzoic 147 

" Nitrous 246 

" Oleic 262, 263 

*' Oxalic 248, 276 

" Palmitic 263 

" Perchloric 154 

" Permanganic 204 

" Phosphoric 187, 188 

" Phthalic 276 

*« Pinic 269 

*' Prussic 271 

•* Pyroacetic 239 

" Pyrogallic 251 

*' Pyroligneous 238 

" Salt 180 

" Silicic 166 

" Stannic 223 

•« Stearic 262, 263 

" Sulpuindigotic 275 

" Sulphindylic 275 

" Sulphinic 170-172 

" Sulphurous 169 

" Syloic 269 

" Tartaric 248 



INDEX. 



301 



Acid, Titanic 222 

Acids 128, 129 

" Vegetable 229,248 

Acrolein 261 

Action of Oxygen and Water 

on Metals 178 

Adhesion 13 

Affinity, Chemical 123 

Laws of 295 

Air, Atmospheric 144 

" Dissolved in Water 142 

Albumen 277, 278 

Albuminose 279 

Albuminous Bodies 278 

-alcohol, Amylic 236 

*' Benzoic 246 

«' Butylic 236 

*' Cinnamylic 247 

Methylic 236 

«' Propylic 236 

Wine 236 

A-lcohols 236 

Aldehyde 238 

Alizarin 276 

Alkali, Dulcified 183 

Alkalies, Organic 251 

Vegetable 183 

Alkaloids 251 

" Artificial 255 

Alkarsin 244 

Alloys, Fusible 214,218 

*' Type Metals 223 

Allyl 270 

" Sulphide of 270 

** Sulphocyanide of. 270 

Alumina, Salts of. 201 

Silicates of 199 

Aluminum 198 

*' Sesquioxide of.... 198 

Amalgam, Ammoniacal 190 

Amalgamation 104 

Amber 269 

Ammonia 149 

** Carbonate of. 191 

<* Cyanate of 272 

♦' Muriate of 190 

Ammoniacal Amalgam 190 

Salts 191 

Ammonias 255 

Amyl 257 

" Ethyl 255 

26. 



Ammonias, Methyl 257 

" Phenyl 258 

Ammonium 190 

" Chloride of. 190 

" Oxide of. 190 

Tetrethyl, Hy- 
drated Oxide.. 256 

Amyl 245 

Amylaceous and Saccharine 

Bodies 229 

Analyzer 64 

Aniline 284, 247, 276 

Animal Electricity 121 

Aniseed Oil 268 

Antimoniuretted Hydrogen.. 224 

Antimony 223 

Ant-ozone and Ozone... 136,137 
Archil, Turnsol or Cudbear. 276 

Argentiferous Galena 225 

Armature 91 

Arsenic 220 

" Acid 221 

«* Bisulphide of 221 

" Marsh's Test for 221 

" or Ratsbane 221 

" Reinsch's Test for... 222 
Arsenical Sulphide of Iron.. 220 

Art of Dyeing 274 

Artificial Alkaloids contain- 
ing several Compound 

Radicals 259 

Artificial Alkaloids Homo- 
logous with Aniline 258 

Atmospheric Air 144 

Atom 292 

Atomic Weight 295 

Attraction, Capillary 13 

B. 

Balsam, Canada 270 

Peru 270 

" Tolu 270 

Balsams and Resins 269 

Barium 192 

" Chloride of 192 

Barometer Double 89 

Baryta 192 

" Nitrate of 192 

" Sulphate of 192 

Bases 129, 130 

" Artificial Orgauic 256 



302 



INDEX. 



IJaies, Vegetable... 229 

Batteries, Electro - Motive, 

Forces of 101 

Batteries, Thermo-Electric. 1?.0 

Battery, Bunsen 99 

Daniel's.... 98 

♦' Electropoion 100 

Gas 102 

♦' Gas and Secondary 

Piles 109 

♦* Grove 99 

** Iron or Maynooth.. 100 

*' Sraee's 97 

Beeswax 264 

Benzoic Acid 246 

" Alcohol 246 

Benzol 334-247 

" Nitro 247 

Benzoyl 246 

Bergamot, Oil of 267 

Bessemer's Process 207 

Biborate of Soda 189 

Bichromate of Potassa 212 

Biethylamine *256 

Bile 281 

Bilin 281 

Binaries 127 

Binoxide of Hydrogen 143 

Bismuth. 217 

Bisulphide of Carbon 165 

Iron 206 

Bitter Almonds 268 

Bleaching Powder or Chlo- 
ride of Lime 194 

Blood 280 

«* Analysis of the 280 

" Serum of the 280 

Blowpipe, Oxyhydrogen 140 

Blue Ink 273 

'* Prussian 273 

*' Saxon 275 

'* Turnbull's 273 

" Vitriol 215 

Bodies, Albuminous 279 

" Diamagnetic 92 

*« Found in Water 142 

♦* Magnetic 92 

Boracic Acid 165 

Borax 189 

'< Biborate of Soda 189 

Borneene - 268 



Boron 165 

Brazil-Wood 267, 277 

Breaking Weights, Table of 290 

Brezeline 27 S 

Brittleness of Metals 177 

Bromine 155 

Brucia 254 

Bunsen Battery, Modified 

Forms of 100 

Bunsen and Kirchoff, Ana- 
lysis of the Sun 57 

Burning Fluid 267 

Butyl 245 

Butyric Acid 235, 264 

Butyrin 264 

C. 

Cadet's Fuming Liquid 244 

Cadmium 214 

" Sulphide of 214 

" Iodide of 214 

Caesium 202 

CaflPeine or Theine 255 

Calcium 193 

" Chloride of 194 

Calomel 225 

Calorimeter, Hare's 96 

Camphene 267 

Camphoric Acid 269 

Camphors 268 

" Borneo 268 

*' Japan 268 

Canary Glass, Fluorescence 

of 58 

Cundle Making, Process of... 263 
'* *' Wilson's Pro- 
cess 263 

Cannon, Electrical 86 

Caoutchouc 270 

Capillary Attraction 13 

Capric Acid 264 

Caproic and Caprylic Acid.. 264 

Caramel 234 

Carbolic Acid or Phenol 234 

Carbon 158 

" Amorphous 169 

" Bisulphide of. 165 

" Metalic 169 

" and Nitrogen, Com- 
pound of 164 



INDEX. 



103 



Carbon and Sulphur, Com- 
pound of 165 

Carbonic Acid 160,161 

" Liquid 161 

Acid, Solid 162 

Oxide 160 

Carburetted Hydrogen 238 

Carre's Apparatus 31 

Casein 277-279 

Cast Iron .% 206 

Cedar-Wood Oil 268 

Cedrene 268 

Cells 95 

Centigrade into Fahrenheit 

291, 292, 293 

Cerin 264 

Cerium 201 

Cerotyl, Oxide of 264 

Cetin 264 

Cetyl, Oxide of. 264 

Charcoal 159 

" Animal 159 

Chemical AflBnity 123, 124 

'* Combination, Laws 

of 295-297 

" Physics 9 

Chemistry 123 

'* Inoreanic 125 

Organic 228 

Chime of Bells, Electric 77 

Chloracetic Acid 239 

Chloral 240 

Chloric Acid 154 

Chloride of Nitrogen 155 

Chlorine 151, 152 

** Bleaching 153 

*' and Oxygen 154 

*♦ Test for 153 

Chlorophyle 277 

Chlorous Acid 154 

Cholesterin 280 

Chondrin 279 

Chromate of Lead 212 

Chromatic Aberration, its 

Correction 61 

Chromic Acid 211 

Chromium 211 

Cinchona 253 

Cinchonia 252 

Cinchonicine 253 

Cinchonidine 253 



Cinnamic Acid 247 

Cinnamon, Oil of , 247 

Cinnamyl 247 

Cinnamylic Alcohol „ 247 

Circularly Polarized Light.. 71 

Citric Acid 249 

Classification of Metals 179 

Coal-Tar 233 

Oil 283 

Cobalt 209 

" Chloride of 210 

Cobaltcyanngen 273 

Cochineal 277 

Cohesion 13 

Coil, Medical Induction 117 

Coil, Ruhmkorff 117 

Coils and Solenoids, Mag- 
netic Properties of. Ill 

Coke 159 

Collodion 232 

Colophony or Rosin 269 

Coloring Principles, Organic 274 

Columbium 224 

Compass, Tangent 113 

Complementary Colors 54 

Condensation 32 

Condenser of Fizeau 118 

Conducting Power of Solids, 

Table of 84 

Conducting Power of Gases 34 
" "of Sub- 
stances for Electricity.. 74 
Conduction of Electricity... 83 

" • Heat 33 

Conductors and Insulators.. 74 

Conia 255 

Contraction, Application of. 23 

Convection, Electricity 83 

Heat 35 

Copaiba, Oil 267 

Copal 269 

Copper 214, 215 

" Black Oxide of 215 

*' Pyrites 214, 215 

** Sulphate of 215 

Corpuscles, Red 280 

White.. 280 

Corrosive Sublimate 225 

Couples, Galvanic 95 

Creosote 283 

Criopherous 81 



304 



INDEX. 



Crystallin ... 279 

Crystallography 16 

Culinary — Paradox 28 

Curd 279 

Current, Primary 115 

** Secondary 115 

Currents 119 

'* Moving in Wires, 

Properties of 110 

Cyanic Acid 271 

Cyanide of Gold 271 

" Mercury 271 

*' Silver 271 

Cyanogen 164, 230 

" and its Compounds 

271-274 

** with Iron, Com- 
pounds of 272 

" with Oxygen, Com- 

pouads of 271 

Cyanol 234 

Cyanuric Acid 272 

D. 

Dammar-Resin. 269 

Daniel's Hygrometer 146 

Density 11 

" of Gases 12 

" of Liquids 11 

" of Solids 11 

Dew Point 146 

Dextrine 232 

Diamond 158 

Didymium 201 

Discharge 84 

'♦ Disruptive 84 

*' Flame 84 

Glow 87 

Discharger, Universal 85 

Diffraction 40 

Diffusion of Liquids and 

Gases 14 

Dispersive Powers 60 

« " Table of... 60 

Distillation 33 

Distribution of Electricity... 80 

Double Fluid Theory 72 

Double-image Prism 51, 294 

Double Refraction 50 

" " in Glass... 51 



Double Refraction in Ice- 
land Spar 50 

Double Refraction in Quartz 51 

Drummoud Light 194 

Dyeing, Art of. 274 

Dyalysis 14 

E. 
Earths, Metals of the Alka- 
line 192 

Effects of Heat 21 

Elaioptene 266 

Electric Egg 59 

" Lamp, Duboscq's... 106 
Electrical Attraction and Re- 
pulsion 76 

Electrical Machine 75 

" Relation of Sub- 
stances, Table of 73 

** Umbrella 73 

Electricity 71 

" Animal 121 

♦' Induction of. 81 

" Statical 72 

Electrodes or Poles 96 

Electrolysis 108 

Electro-Magnet 92 

Gilding 109 

" Plating 109 

Electrometer, Coulomb's 79 

Electrophorus 81 

Electroscope, Gold-leaf 79 

Electrotyping 109 

Elements 125 

*< Electro - chemical, 

Order of. 95 

*' Nomenclature of... 126 

" Symbols of 127 

'« Table of 126 

Elemi Oil 267 

Elliptically Polarized Light. 71 

Erbium 201 

Essences 266 

Essential Oils, Hydrocarbon. 267 
" *• Oxy hydrocar- 
bon 268 

" *' containing 

Sulphur 270 

" or Volatile Oils 265 

" or Volatile Oils, 

Classification of. 266 



INDEX. 



305 



Etching by Hydrofluoric 

Acid 157 

Ether, Hydrobromic 242 

" Hydrochloric 242 

♦* Nitric 242 

*' Oxalic 242 

Sulphuric 238 

Ethyl 229 

" Ammonias 255 

" Compounds 243 

" Methyl 242 

Ethylamine 255 

Evaporation 32 

Exciting Liquids 95 

Expansion 21 

" Applications of ... 23 

" in Freezing 26 

" of Gases 22 

«« of Liquids 22 

of Solids 22 

Extension 283 

Extra-Currents 119 

F. 

Fats 261 

Fermentation 235 

Ferric Acid 206 

Ferricyanide of Potassium.. 273 

Ferricyanogen 273 

Feriocyanide of Potassium. 272 

Ferrt'Ncyanogen 272 

Ferrous Salts 209 

Fibrin 277, 278 

Fireed Oil 261 

Fizeau's Condenser 118 

Flameless Lamp 227 

Fluid Burning 267 

Fluorescence 58 

Fluorine 156 

Fly Powder 221 

Formation of Images by 

Lenses 48 

Formic Acid 241 

Fowler's Solution 221 

Praunhofer's Lines 54 

Freezing, Congellation 25 

" Mixtures 24 

«' " Table of. 25 

Fulminic Acid 271 

Fusel-Oils 241 

26* 



Fusible Metal 218 

Fusion 23 

Fustic Wood 277 

G. 

Gallic Acid 251 

Galvanic Batteries 96 

" " Manage- 

ment of 102-104 
*« Current, Chemical 

Effects of 107 

Galvanic Currents, Effects of 105 
" " Velocity 

in Good Conductors 111 

** Induction 114 

Galvanism 94 

Galvanometer 113 

Gas, Illuminating 233 

Gases, Conducting Power of 34 

*' Density of 12 

" Diffusion of 14 

" Transpiration of 14 

Gassiot's Cascade 58 

Gastric Juice 281 

Gelatin 279 

General Properties of Matter 9 

Ghost 42 

Glass... 200 

" Soap for 221 

" Stained 69 

Glucinum 201 

Glucose. 232 

Glycerin 264 

Gold 226 

'• Mosaic 223 

Graphite or Plumbago 158 

Gravitation 10 

Gravity 10 

" Specific 10 

Green, Scheele's 221 

*' Schwunfurt 221 

" Vitriol 208 

Gum 231 

•♦ Arabic 231 

'* Benzoin 270 

" Elastic 270 

<« Lac 269 

'♦ Senegal 231 

" Tragacanth 231 

Gun-cotton or Pyroxyline... 232 



306 



INDEX. 



Gunpowder 185 

Gntta-Percha 270 

Gypsum 195 

H. 

Haloid Salts 242 

Hardness of Metals 177 

Heat 16 

" Animal 18 

" Effects of 21 

'* Measurement of 18 

" Sources of. 17 

Hematoxylin 276 

Hydrated Nitric Acid 147 

" Oxide of Tetre- 

thylammonium 256 

Hydro-Carbons 162 

" *' Neutral 234 

Hydrocliloric Acid 154, 155 

Hydro-Electric Machine 76 

Hydroferrocyanic Acid...... 272 

Hydrofluoric Acid 157 

Hydrogen Antimoniuretted. 224 

" Bicarburetted 162 

" Binoxide of. 140 

" Organ 140 

** with Oxygen, 

Compounds of. 141 
" Protocarburetted 162 

<' Sulphuretted 217 

Hydrometer 12 

Hydrosulphocyanogen 274 

Hydrosulphuric Acid 173 

Hygrometer, Daniel's 146 

«' Regnault's 144 

Hypochloric Acid 154 

Hypoehlorous Acid 154 

Hyponitric Acid 147 

Hyposulphurous Acid 172 

I. 

Iceland Spar 195 

India-Rubber 270 

" '* Vulcanized 270 

Indigo 275 

" White 275 

Indigoferra 275 

Indigotine 275 

Indium 202 

26* 



Induction of Electricity 81 

" Galvanic 114 

Ink, Black 212, 251 

" Blue 251, 273 

" Red 277 

Inorganic Chemistry 125 

Interference 39 

Iodine....- 156 

Iridium 228 

Iron 205 

" Cast 206 

** Compounds of 206-203 

Isomeric Bodies 253 

J. 

Juice, Gastric 281 

Juniper Oil 267 

K. 

Kakodyl 244 

Oxide of 244 

Keratin 279 

&eatin 279, 280 

L. 

Lac, or Gum Lac 269 

«' Seed 269 

" Stick 269 

Lactic Acid 235 

Lake 274 

Lampblack * 159 

Lanthanum 201 

Latent Heat 24 

" " of Gases 29 

" " of Liquids.... 23, 24 
Laws of Chemical Combina- 
tion 295-297 

Lead and Compounds... 215-217 

«' Red 217 

Lemon Oil 267 

Leucoline .' 234 

Leyden Jar 32 

Light. 37 

" Circularly Polarized... 71 

** Drummond 194 

" Elliptically Polarized, 71 

" Lime 140 

" Propagation of 38 

*' Properties of Plane 

Polarized 64 



INDEX. 



307 



Light, Sources of 37 

Velocity of 38 

Lightning Rods 80 

Lignine of Wood, etc 231 

Lime and Compounds... 193-195 

" Light 140 

Liquefaction 32 

Liquids, DifiFusion of. 14 

" Latent Heat of 28 

Lithium 189 

Litmus, Archil, Turnsol, or 

Cudbear 276 

Loadstone 90 

Logwood 276, 277 

M. 

Madder 276 

" Purple 276 

«♦ Red 276 

Magnesia and Com- 
pounds ... 197, 198 

" Citrate of. 250 

♦* Phosphate of Am- 
monia and 197 

Magnesium and Com- 
pounds... 196, 197 

Wire 196 

Magnet 113 

Artificial 90 

*' Dr. Jayne's 93 

Magnetic Properties of Coils 

or Solenoids Ill 

Magnetism 89 

" by Induction 94 

Magnetizing Effects 110 

Magneto-electric Machine... 116 

Magnets, Horseshoe 91 

Malic 249 

Manganese and Com- 
pounds 202, 203 

Margaric Acid 262, 263 

Margarin 262, 263 

Mass 10 

Mastic 269 

Matter, Extension, Bulk, or 

Volume 9 

*' Figure 10 

" General Properties 

of 9 

" Impenetrability of... 10 



Matter Indestructible 10 

Meconic Acid 252 

Medical Induction Coil 117 

Medicated Waters 265 

Measurement of Heat... 18 

Measures of Capacity, French 

and English 286 

" of Capacity in the 

United States ... 284 

Cubic 285 

Dry 285 

♦* French and Eng- 
lish 285, 286 

" for Length 285 

Liquid 285 

of Surface 284 

" of Weight in the 

United States 287 

" of Weight, French 

and English 288 

Mechanical Forces 10 

Melissic Acid 264 

Melissyl, Oxide of. 264 

Mercaptan 240 

Mercury 224 

" Cyanide of 271 

«' Bromide of. 225 

** Iodide of 225 

" Subchloride of 225 

Metal 278 

Metals 177 

*' Chemical Properties 

of 178 

" Classification of 179 

" Color of 177 

" Ductility and Mallea- 
bility 178 

«* Fusible 218 

*♦ Hardness,Brittleness, 

and Tenacity 177 

** Malleability and Duc- 
tility *..... 178 

" of the Alkaline E.irths ll'-J 

" Smell and Taste 177 

" Specific Gravity of ... ITS 

Metaphosphate of Sodn 188 

Mctngallic Acid 251 

Mctastannic Acid 2'Jo 

Methyl 229 

*' Compounds of. 224 

'' Ethers 2:4 



308 



INDEX. 



Mothylic Alcohol 240 

Mrk 281 

Mispickel 220 

Mixture of Nitrogen with 

Oxygen 144 

Molasses 234 

Molybdenum 219 

Mordant 274 

Morphia 252 

Mosaic Gold 223 

Mucilage 231 

Muriate of Ammonia 90 

Muscovin 279 

N. 

Naphthalin 234 

Needle, Astatic 92 

" Masrnetic 92 

Neutral Bodies 130 

Newton's Rings 44 

Nichols' Prism 63 

Nicotina 255 

Nitric Acid 147 

" Oxide 146 

Nitrogen 143, 144 

" Chloride of. 155 

" and Hydrogen, Com- 
pounds of 149 

Nitrous Acid 147 

Oxide 146 

Nomenclature of Elemeuts.. 126 



Oil of Aniseed 

Bergamot 

Bitter Almonds 

Cedar-wood 

Cinnamon 247, 

Coal-tar 

Copaiba 

Cubebs 

Cumin 

Elemi 

Fusel 

Garlic 

Juniper.. 

Lemon 

Mustard 

Orange-peel 



268 
267 
268 
269 
268 
233 
267 
267 
267 
267 
241 
270 
267 
267 
270 
267 



Oil of Pepper 267 

" Eue 268 

" Thyme 268 

*' Turpentine 267 

" Valerian 268 

" Wintergreen 268 

Oils 229, 260 

" Classification of. 260 

" Vegetable and Animal.. 260 
" Essential, containing Sul- 
phur 270 

" " or Volatile... 230 

" Fixed 261 

Olein 262, 263 

Oleic Acid 262, 263 

Orange-peel Oil 267 

Orcein 276 

Organ, Hydrogen 140 

Organic Alkalies or Alkaloids 251 
'* " Table of.... 252 

" Bases 241 

" "or Alkaloids, 

" Artificial 255 

" Coloring Princi- 
ples .. 230, 274 
" " Matters, 
the most impor- 
tant 275 

Osmium 228 

Ostein 279 

Oxalic Acid 248, 276 

Oxide, Carbonic 160 

" of Cerotyl 264 

Cetyll 264 

Kakodyl 244 

" Melissyl 264 

" Nitric 146 

" Nitrous 146 

Oxyhydrogen Blowpipe 140 

Oxygen 131 

" Preparation of.. 131-135 

'* Properties of 135 

Ozone and Ant-ozone... 136, 137 

P. 

Paraffine 233 

Paranaphthalin 234 

Palladium ^ 227 

Palmitin 263 

Palmitic Acid 263 



INDEX. 



309 



Pnncruatin 279 

Pearlash 183 

Peat S82 

Pepper, Oil of 267 

Pepsin 281 

Perchloric Acid 154 

Permanganic Acid 204 

Peruvian Bark 253 

Pheyol 234 

Phosphorescence 59 

Phosphoric Acid 187, 188 

Phosphorus 174, 175 

" and Iodine 177 

«' Oxide of.... 175, 176 

Phosphuretted Hydrogen Gas 176 

Phthalic Acid 276 

Picoline 234 

Picro-erytherin 276 

Pile, Dry 101 

Piles, Secondary, and Gas 

Battery 109 

Pinic Acid 269 

Pitch 233 

Pitch-balls, Dancing 78 

Plane Polarized Light 62 

" «* " Color- 

ed Effects of 76 

Plaster of Paris 195 

Platinum 226 

" Sponge 227 

♦' Wire 227 

Plumbago or Graphite 158 

Polarity 16 

Polarized Light 62 

Polarizer 64 

Poles or Electrodes 96 

Potash, Chlorate of 185 

" Red Prussiate of.... 273 

♦' Yellow Prussiate of.. 272 

Potassa and Compounds 183, 184 

Potassium 181 

j& " Ferricyanide of... 273 

M^ n Ferrocyanide of.. 272 

Powders, Seidlitz 187 

Properties of Currents, mov- 
ing freely in Wires 110 

Properties of Plane Polar- 
ized Light 64 

Propyl 245 

Protem 277 

Protochloride 212 

1 



Protosulphide of Iron 206 

Protoxide of Iron 205 

Primary Current 115 

Prism, Double-image 51, 284 

" Hollow 53 

" Nichols' 63 

Prussian Blue 273 

" " Basic 273 

" *' Ordinary 273 

Prussic Acid 271 

Purpurin 276 

Pyroacetic Acid 239 

Pyrogallic Acid 251 

Pyroligneous Acid 238 

Pyrophosphate of Soda 188 

Q. 

Quercitron 277 

Quinia 253 

'' Muriate of 253 

" Sulphate of. 253 

Quinidine 253 

Quinoidine 253 

R. 

Radiant Heat „ 86 

Radiation 36 

Rainbows, Artificial 52 

Red Lead 217 

" Prussiate of Potash 273 

*' Turkey 276 

Reflection 41 

Refraction 45 

Regnault's Hygrometer 144 

Rennet 279 

Repulsion 15 

Resin, Dammar 269 

Resins 266 

" and Balsams 269 

Revolving Arch, Thermo- 
electric 121 

Rhodium 228 

Rocellium 276 

Rochelle Salt 249 

Rock Candy 234 

Rosin 267 

" or Colophony 269 

Rotation of the Polarized 

Ray 69 



olO 



INDEX. 



Rubidium 202 

Rue Oil 268 

Ruhmkorff Coil 117 

Ruthenium 228 

S. 

Saccharimeter 70 

Sachfirine and Amylaceous 

Bodies 229,230 

Saffron 277 

Salaeratus 188 

Sal Ammoniac... 190 

Salicin 247 

Salicyl 247 

Salicylate 268 

Saliva 281 

Salt, Basic 180 

" Glauber 187 

" Rochelle 187 

" Tribasic 180 

" of Tartar 249 

Salts 179 

" Acid 180 

<< Ammoniacal 191 

** Bibasic 180 

«« Double 180 

" Ferrous 209 

*' Monobasic 180 

" Neutral, 180 

Sandarac 269 

Saponification 262 

Saxon Blue 275 

Sealing-wax 269 

Secondary Current 115 

Seidlitz Powders 187 

Selenium 174 

Selenocyanogen 274 

Seroline .. 280 

Sesquioxide of Iron 205 

Shellac 269 

Silicic Acid 166 

Silicon 166 

»* Compound with Oxy- 
gen 167 

Silver and Compounds 225 

" Cyanate of 272 

«♦ Cyanide of 271 

«* Cyanurateof 272 

«' Fulminate of 272 

Soap-making, Process of. 263 



Soda and Compounds ... 186-188 

Sodium 186 

" Chloride of 186 

Solenoid.... 113 

Solenoids or Coils, Magnetic 

Properties of Ill 

Specific Heat 20 

" " of Gases and 

Vapors Compared with 

Water 21 

Specific Heat of Solids and 

Liquids, Tabl<e of 21 

Spectroscope 56 

Spectrum 53, 54 

" Analysis 55 

Spermaceti 264 

Spermatin 279 

Spherical Aberration 49 

Spheroidal State 34 

Stannate of Soda 223 

Stannic Acid 223 

Starch 230 

Statical Electricity 72 

Stearic Acid.... 262, 263 

Stearin 262, 263 

Stearoptene 266 

Strontium 193 

Strychnia 254 

Sublimation 33 

Sugar 234 

" Barley 234 

" Cane 2.34 

" Grape 234 

Sulphindigotic Acid 275 

Sulphindylic Acid 275 

Sulphocyanogen 273 

Sulphur 168 

Sulphuric Acid 170-172 

Sulphurous Acid 169 

Sun, Analysis of 57 

Supercarbonate of Soda 187 

Symbols of Elements 127 

Sylvic Acid 269 

Synovin 279 

T. 

Table of Breaking Weights.. 290 
" of Centigrade Degrees 

into Fahrenheit, 291-293 
** of Conducting Power 

of Solids 84 



INDEX. 



311 



Table of Dispersive Powers 60 
'« of Electrical Rela- 
tions of Substances, 73 
" of Electro-chemical 

Order of Elements, 95 

of Elements 126 

of Fahrenheit Degrees 

into Centigrade, 291-294 
of Indices of Refrac- 
tion 45,46 

of Measures 284-286 

of Organic Alkalies or 

Alkaloids 252 

of Reflecting Powers, 43 
of the Specific Heat of 
Gases and Vapors 
Compared with 

Equal Weight of 

Water 21 

of the Specific Heat of 
Solids and Liquids, 20 

" of Tenacity 290 

** of Weights 287 

Tangent Compass 113 

Tantalum 224 

Tartar Emetic 224, 249 

Tartar, Salt of 183 

Tartaric Acid 248 

Telegraph, Morse's 110 

Tellurium 220 

Tenacity of Metals 177 

" Table of, 290 

Terbium 201 

Ternaries 130 

Thalium 202 

Theine 255 

Theory of the Double Fluid, 72 
Thermo-electric Revolving 

Arch 121 

«« Electricity 120 

** Multiplier 121 

Thermometers 18 

" Centigrade... 19 

«' Fahrenheit... 19 

** Mercurial 19 

♦♦ Spirit 19 

Thorium 201 

Thyme Oil 258 

Tin 222 

«' Compounds of 222,223 

«« Cry of 222 



Tin Stone 222 

Titanic Acid 228 

Titanium, Compounds 222 

Toluol 234 

Transfer of Electricity 83 

Heat 33 

Transpiration of Gases 14 

Triethylamine 256 

Tube Aurora 87, 88 

Tubes, Geissler 87, 88 

Turkey Red '276 

Turpentine 267 

Oil 267 

-' Spirits of 267 

" Venice 270 

Turmeric 277 

Turnsol or Cudbear and Ar- 
chil 276 

Tungsten 219 

Type Metal 223 

U. 

Undulations of Light, Length 

of 55 

Uranium 218 

V. 

Vacuum, Absolute 89 

Valeral 268 

Valerian Oil 268 

Vanadium 219 

Vaporization 26 

Vegetable Acids 248 

Velocity of Galvanic Cur- 
rents for Good Con- 
ductors Ill 

Venice Turpentine 270 

Veratria 254 

Vermilion 226 

Vinous or Alcoholic 235 

Viscous 235 

Vitriol, Green, White 213 

W. 

Water, Air dissolved in 142 

•' Other bodies found 

in 142 

" Hard , 187 



10, 



312 

Water, Spring and Well... 
Waters, Medicated 

" Perfumed. .• 

Wax, Sealing 

Weight 

" Apothecaries' 

• » Av'-irdup'>is 

♦ • Comparative Tables 

of 

'* Troy 

White Vitriol... 

Wintergreen Oil 



INDEX. 



Wood, 



143 

265 
265 
269 
287 
287 
287 

288 
287 
213 
268 



Brazil ll^„ 

Ether 

Fustic 

Log 

Naphtha 

Spirit 



236 
277 
276 
240 
236 



X. 



Xyloidin. 



Yellow, King's ••• 

<' Prussiate of Potash. 
«* Turner's 

Yttrium.. 



232 



221 

272 
217 
201 



Zinc 



212 



Red Oxide of 212 

Silicate of 21L 

Sulphate of 213 

^^^^^ :::::::::■ m 



Zirconium 



465 







° 003 836 399 2 % 



